Open Access

Complete genome sequence of Staphylothermus hellenicus P8T

  • Iain Anderson1Email author,
  • Reinhard Wirth2,
  • Susan Lucas1,
  • Alex Copeland1,
  • Alla Lapidus1,
  • Jan-Fang Cheng1,
  • Lynne Goodwin1, 3,
  • Samuel Pitluck1,
  • Karen Davenport1, 3,
  • John C. Detter1, 3,
  • Cliff Han1, 3,
  • Roxanne Tapia1, 3,
  • Miriam Land4,
  • Loren Hauser4,
  • Amrita Pati1,
  • Natalia Mikhailova1,
  • Tanja Woyke1,
  • Hans-Peter Klenk5,
  • Nikos Kyrpides1 and
  • Natalia Ivanova1
Standards in Genomic Sciences20115:5010012

DOI: 10.4056/sigs.2054696

Published: 15 October 2011

Abstract

Staphylothermus hellenicus belongs to the order Desulfurococcales within the archaeal phylum Crenarchaeota. Strain P8T is the type strain of the species and was isolated from a shallow hydrothermal vent system at Palaeochori Bay, Milos, Greece. It is a hyperthermophilic, anaerobic heterotroph. Here we describe the features of this organism together with the complete genome sequence and annotation. The 1,580,347 bp genome with its 1,668 protein-coding and 48 RNA genes was sequenced as part of a DOE Joint Genome Institute (JGI) Laboratory Sequencing Program (LSP) project.

Keywords

Archaea Crenarchaeota Desulfurococcaceae hyperthermophile hydrothermal vent anaerobe

Introduction

Strain P8T (=DSM 12710 = JCM 10830) is the type strain of the species Staphylothermus hellenicus. It was isolated from a shallow hydrothermal vent at Palaeochori Bay near the island of Milos, Greece [1]. There is one other validly named species in the genus, S. marinus, for which a complete genome sequence has been determined and published [2,3]. The S. hellenicus genome is the ninth to be published from the order Desulfurococcales in the phylum Crenarchaeota. The only other genus in the Desulfurococcales for which two species have been sequenced is Desulfurococcus. Figure 1 shows the phylogenetic position of S. hellenicus with respect to the other species in the order Desulfurococcales.
Figure 1.

Phylogenetic tree highlighting the position of S. hellenicus relative to the type strains of the other species within the order Desulfurococcales. The tree was inferred from 1,333 aligned characters [4,5] of the 16S rRNA gene sequence under the maximum likelihood (ML) criterion [6]. Rooting was done initially using the midpoint method [7] and then checked for its agreement with the current classification (Table 1). The branches are scaled in terms of the expected number of substitutions per site. Numbers adjacent to the branches are support values from 1,000 ML bootstrap replicates [8] (left) and from 1,000 maximum parsimony bootstrap replicates [9] (right) if larger than 60%. Lineages with type strain genome sequencing projects registered in GOLD [10] are labeled with one asterisk, those listed as ‘Complete and Published’ with two asterisks.

Organism information

S. hellenicus was isolated from sediment at Palaeochori Bay, Milos, Greece [1]. For isolation, 1 ml of sediment was added to half-strength SME medium [11] with 2% elemental sulfur and incubated at 90°C under H2/CO2. Colonies were isolated on plates with the same medium and with 1% Phytagel and 2–3% sodium alginate added [1]. S. hellenicus is a regular-shaped coccus (Figure 2) which can form large aggregates of up to fifty cells, similar to S. marinus [1,12]. No flagella were observed and cells were nonmotile. The temperature range for growth of S. hellenicus is 70–90°C, with an optimum at 85°C [1]. The salinity range was from 2% to 8% NaCl, and the optimum was 4% NaCl [1]. The pH range for growth was from 4.5 to 7.5. The optimum pH was 6.0 [1]. S. hellenicus is a strict anaerobe, and can grow under H2/CO2 or N2/CO2 [1]. It is a heterotroph which grows well on yeast extract but poorly on peptone [1]. Many carbon sources were tested, but no growth was observed, showing that a complex nutrient source is required [1]. Elemental sulfur was required for growth [1]. The features of the organism are listed in Table 1.
Figure 2.

Scanning electron micrograph of S. hellenicus P8T.

Table 1.

Classification and general features of S. hellenicus P8T according to the MIGS recommendations [13]

MIGS ID

Property

Term

Evidence codea

 

Current classification

Domain Archaea

TAS [14]

 

Phylum Crenarchaeota

TAS [15,16]

 

Class Thermoprotei

TAS [16,17]

 

Order Desulfurococcales

TAS [16,18]

 

Family Desulfurococcaceae

TAS [1921]

 

Genus Staphylothermus

TAS [12,22]

 

Species Staphylothermus hellenicus

TAS [1]

 

Type strain P8

TAS [1]

 

Cell shape

coccus

TAS [1]

 

Motility

nonmotile

TAS [1]

 

Sporulation

nonsporulating

NAS

 

Temperature range

70–90°C

TAS [1]

 

Optimum temperature

85°C

TAS [1]

MIGS-6.3

Salinity

2–8% NaCl (optimum 4%)

TAS [1]

MIGS-22

Oxygen requirement

anaerobe

TAS [1]

 

Carbon source

yeast extract

TAS [1]

 

Energy metabolism

heterotrophic

TAS [1]

MIGS-6

Habitat

marine geothemally heated areas

TAS [1]

MIGS-15

Biotic relationship

free-living

TAS [1]

MIGS-14

Pathogenicity

none

NAS

 

Biosafety level

1

NAS

 

Isolation

geothermally heated sediment

TAS [1]

MIGS-4

Geographic location

Palaeochori Bay, Milos, Greece

TAS [1]

MIGS-5

Isolation time

September 1996

TAS [1]

MIGS-4.1

Latitude

36.674

 

MIGS-4.2

longitude

24.517

TAS [1]

MIGS-4.3

Depth

4–10 m

TAS [1]

MIGS-4.4

Altitude

not applicable

 

a) Evidence codes - IDA: Inferred from Direct Assay; TAS: Traceable Author Statement (i.e., a direct report exists in the literature); NAS: Non-traceable Author Statement (i.e., not directly observed for the living, isolated sample, but based on a generally accepted property for the species, or anecdotal evidence). These evidence codes are from the Gene Ontology project [23].

Genome sequencing information

Genome project history

This organism was selected for sequencing on the basis of its phylogenetic position and is part of a Laboratory Sequencing Project (LSP) to sequence diverse archaea. The genome project is listed in the Genomes On Line Database [10] and the complete genome sequence has been deposited in GenBank. Sequencing, finishing, and annotation were performed by the DOE Joint Genome Institute (JGI). A summary of the project information is shown in Table 2.
Table 2.

Genome sequencing project information

MIGS ID

Property

Term

MIGS-31

Finishing quality

Finished

MIGS-28

Libraries used

Illumina standard library, 454 standard library, 454 28 kb paired end library

MIGS-29

Sequencing platforms

Illumina GA II, 454 GS FLX Titanium

MIGS-31.2

Sequencing coverage

462× with Illumina, 132× with 454

MIGS-30

Assemblers

Velvet, Newbler, phrap

MIGS-32

Gene calling method

Prodigal, GenePRIMP

 

INSDC ID

CP002051

 

Genbank Date of Release

June 1, 2010

 

GOLD ID

Gc01350

 

NCBI project ID

33683

MIGS-13

Source material identifier

DSM 12710

 

Project relevance

Phylogenetic diversity, biotechnology

Growth conditions and DNA isolation

S. hellenicus P8T cells were grown in a 300 liter fermenter at 85°C in SME medium [11] with 0.1% yeast extract, 0.1% peptone, and 0.7% elemental sulfur under a 200 kPa N2 atmosphere. DNA was isolated with a Qiagen Genomic 500 DNA Kit.

Genome sequencing and assembly

The genome of S. hellenicus was sequenced at the Joint Genome Institute (JGI) using a combination of Illumina and 454 technologies. An Illumina GA II shotgun library with reads of 730 Mb, a 454 Titanium draft library with average read length of 310.5 +/− 187.8 bases, and a paired end 454 library with an average insert size of 28 Kb were generated for this genome. Illumina sequencing data was assembled with Velvet [24], and the consensus sequences were shredded into 1.5 kb overlapped fake reads and assembled together with the 454 data with Newbler. Draft assemblies were based on 208 Mb 454 draft data.

The initial Newbler assembly contained 4 contigs in 1 scaffold. We converted the initial 454 assembly into a phrap assembly by making fake reads from the consensus, collecting the read pairs in the 454 paired end library. The Phred/Phrap/Consed software package was used for sequence assembly and quality assessment [2527] in the following finishing process. After the shotgun stage, reads were assembled with parallel phrap (High Performance Software, LLC). Possible mis-assemblies were corrected with gapResolution (Cliff Han, unpublished), Dupfinisher [28], or sequencing cloned bridging PCR fragments with subcloning or transposon bombing (Epicentre Biotechnologies, Madison, WI). Gaps between contigs were closed by editing in Consed, by PCR and by Bubble PCR primer walks. A total of 23 additional reactions were necessary to close gaps and to raise the quality of the finished sequence.

Genome annotation

Genes were identified using Prodigal [29], followed by a round of manual curation using GenePRIMP [30]. The predicted CDSs were translated and used to search the National Center for Biotechnology Information (NCBI) nonredundant database, UniProt, TIGRFam, Pfam, PRIAM, KEGG, COG, and InterPro databases. The tRNAScanSE tool [31] was used to find tRNA genes, whereas ribosomal RNAs were found by using BLASTn against the ribosomal RNA databases. The RNA components of the protein secretion complex and the RNase P were identified by searching the genome for the corresponding Rfam profiles using INFERNAL [32]. Additional gene prediction analysis and manual functional annotation was performed within the Integrated Microbial Genomes (IMG) platform [33] developed by the Joint Genome Institute, Walnut Creek, CA, USA [34].

Genome properties

The genome includes one chromosome and no plasmids, for a total size of 1,580,437 bp (Table 3 and Figure 3). This genome size is close to the average for Desulfurococcales. The GC percentage is 36.8%, which is lower than most of the Desulfurococcales. A total of 1,716 genes were identified: 48 RNA genes and 1,668 protein-coding genes. There are 69 pseudogenes, comprising 4.1% of the protein-coding genes. About 62% of predicted genes begin with ATG, 30% begin with TTG, and 7% begin with GTG. There is one copy of each ribosomal RNA. Table 4 shows the distribution of genes in COG categories.
Figure 3.

Graphical circular map of the chromosome. From outside to the center: Genes on forward strand (colored by COG categories), genes on reverse strand (colored by COG categories), RNA genes (tRNAs green, rRNAs red, other RNAs black), GC content, and GC skew.

Table 3.

Nucleotide content and gene count levels of the genome

Attribute

Value

% of totala

Size (bp)

1,580,437

100.0%

G+C content (bp)

582,173

36.8%

Coding region (bp)

1,383,053

87.5%

Number of replicons

1

 

Extrachromosomal elements

0

 

Total genes

1,716

 

RNA genes

48

 

rRNA operons

1

 

Protein-coding genes

1,668

100.0%

Pseudogenes

69

4.1%

Genes with function prediction

975

58.5%

Genes in paralog clusters

98

5.9%

Genes assigned to COGs

1,093

65.5%

Genes assigned Pfam domains

1,135

68.0%

Genes with signal peptides

129

7.7%

Genes with transmembrane helices

342

20.5%

CRISPR repeats

3

% of totala

a) The total is based on either the size of the genome in base pairs or the total number of protein coding genes in the annotated genome

Table 4.

Number of genes associated with the 25 general COG functional categories

Code

Value

%agea

Description

J

161

9.7

Translation

A

2

0.1

RNA processing and modification

K

59

3.5

Transcription

L

72

4.3

Replication, recombination and repair

B

2

0.1

Chromatin structure and dynamics

D

7

0.4

Cell cycle control, mitosis and meiosis

Y

0

0.0

Nuclear structure

V

18

1.1

Defense mechanisms

T

20

1.2

Signal transduction mechanisms

M

39

2.3

Cell wall/membrane biogenesis

N

4

0.2

Cell motility

Z

0

0.0

Cytoskeleton

W

0

0.0

Extracellular structures

U

11

0.7

Intracellular trafficking and secretion

O

49

2.9

Posttranslational modification, protein turnover, chaperones

C

79

4.7

Energy production and conversion

G

79

4.7

Carbohydrate transport and metabolism

E

73

4.4

Amino acid transport and metabolism

F

44

2.6

Nucleotide transport and metabolism

H

53

3.2

Coenzyme transport and metabolism

I

15

0.9

Lipid transport and metabolism

P

67

4.0

Inorganic ion transport and metabolism

Q

5

0.3

Secondary metabolites biosynthesis, transport and catabolism

R

194

11.6

General function prediction only

S

116

7.0

Function unknown

-

575

34.5

Not in COGs

a) The total is based on the total number of protein coding genes in the annotated genome.

Comparison with the S. marinus genome

The genome of S. hellenicus is slightly larger than the genome of S. marinus (1.58 Mbp vs. 1.57 Mbp), and the number of protein-coding genes is also larger (1668 vs. 1610). However, the number of pseudogenes is also higher in S. hellenicus (69 vs. 40). Some of the COG categories show different numbers of genes between the two organisms. S. hellenicus has 25 additional genes that do not belong to COGs. S. hellenicus has greater numbers of genes involved in cell wall biogenesis (39 vs. 23), nucleotide transport and metabolism (44 vs. 39) and carbohydrate transport and metabolism (79 vs. 72), while S. marinus has greater numbers of genes in the categories of energy production and conversion (92 vs. 79) and inorganic ion transport and metabolism (85 vs. 67).

The genes involved in cell wall metabolism that are in S. hellenicus but not in S. marinus are genes involved in nucleotide-sugar metabolism and glycosyltransferases, suggesting that S. hellenicus may have a greater variety of sugars attached to glycolipids and glycoproteins. Most of the additional S. hellenicus genes are located within a region of fifty genes on the chromosome (Shell_0865-Shell_0915) that is not present in S. marinus. The additional genes in S. hellenicus involved in nucleotide metabolism include adenylosuccinate synthase, adenylosuccinate lyase, and GMP synthase. Both S. hellenicus and S. marinus lack de novo purine synthesis, but the presence of these three additional enzymes suggests that S. hellenicus may be able to synthesize AMP and GMP from IMP, while S. marinus is unable to do so. The additional genes in carbohydrate transport and metabolism include nucleotide-sugar modifying enzymes that were also included in cell wall metabolism, but they also include a probable β-1,4-endoglucanase (cellulase) from glycosyl hydrolase family 5.

The genes found in S. marinus but not in S. hellenicus belong to the categories of energy production and conversion, and inorganic ion transport and metabolism. They include proteins related to subunits of multisubunit cation:proton antiporters and proteins related to subunits of NADH dehydrogenase and formate hydrogen lyase. These proteins are similar to subunits of mbh, a multisubunit membrane-bound hydrogenase from Pyrococcus furiosus [35], and mbx, a multisubunit complex of unknown function that probably has a role in sulfur reduction, also from P. furiosus [36]. S. marinus has three operons related to mbh and mbx, while S. hellenicus has only one, suggesting that the three operons may be redundant in function in S. marinus. Since S. marinus and S. hellenicus lack other enzymes involved in sulfur reduction, it is possible that these mbh/mbx-related operons play a role in sulfur reduction in these organisms.

Authors’ Affiliations

(1)
DOE Joint Genome Institute
(2)
Microbiology - Archaeenzentrum, University of Regensburg
(3)
Los Alamos National Laboratory
(4)
Biosciences Division, Oak Ridge National Laboratory
(5)
DSMZ - German Collection of Microorganisms and Cell Cultures GmbH

References

  1. Arab H, Völker H, Thomm M. Thermococcus aegaeicus sp. nov. and Staphylothermus hellenicus sp. nov., two novel hyperthermophilic archaea isolated from geothermally heated vents off Palaeochori Bay, Milos, Greece. Int J Syst Evol Microbiol 2000; 50:2101–2108. PubMed doi:10.1099/00207713-50-6-2101View ArticlePubMedGoogle Scholar
  2. Anderson IJ, Dharmarajan L, Rodriguez J, Hooper S, Porat I, Ulrich LE, Elkins JG, Mavromatis K, Sun H, Land M, et al. The complete genome sequence of Staphylothermus marinus reveals differences in sulfur metabolism among heterotrophic Crenarchaeota. BMC Genomics 2009; 10:145. PubMed doi:10.1186/1471-2164-10-145PubMed CentralView ArticlePubMedGoogle Scholar
  3. Anderson IJ, Sun H, Lapidus A, Copeland A, Glavina Del Rio T, Tice H, Dalin E, Lucas S, Barry K, Land M, et al. Complete genome sequence of Staphylothermus marinus Stetter and Fiala 1986 type strain F1. Stand Genomic Sci 2009; 1:183–188. PubMed doi:10.4056/sigs.30527PubMed CentralView ArticlePubMedGoogle Scholar
  4. Castresana J. Selection of conserved blocks from multiple alignments for their use in phylogenetic analysis. Mol Biol Evol 2000; 17:540–552. PubMedView ArticlePubMedGoogle Scholar
  5. Lee C, Grasso C, Sharlow MF. Multiple sequence alignment using partial order graphs. Bioinformatics 2002; 18:452–464. PubMed doi:10.1093/bioinformatics/18.3.452View ArticlePubMedGoogle Scholar
  6. Stamatakis A, Hoover P, Rougemont J. A rapid bootstrap algorithm for the RAxML web servers. Syst Biol 2008; 57:758–771. PubMed doi:10.1080/10635150802429642View ArticlePubMedGoogle Scholar
  7. Hess PN, De Moraes Russo CA. An empirical test of the midpoint rooting method. Biol J Linn Soc Lond 2007; 92:669–674. doi:10.1111/j.1095-8312.2007.00864.xView ArticleGoogle Scholar
  8. Pattengale ND, Alipour M, Bininda-Emonds ORP, Moret BME, Stamatakis A. How many bootstrap replicates are necessary? J Comput Biol 2010; 17:337–354. PubMed doi:10.1089/cmb.2009.0179View ArticlePubMedGoogle Scholar
  9. Swofford DL. PAUP*: Phylogenetic analysis using parsimony (*and other methods), Version 4.0 b10. Sinauer Associates, Sunderland, 2002.Google Scholar
  10. Liolios K, Chen IM, Mavromatis K, Tavernarakis N, Hugenholtz P, Markowitz VM, Kyrpides NC. The Genomes On Line Database (GOLD) in 2009: status of genomic and metagenomic projects and their associated metadata. Nucleic Acids Res 2010; 38:D346–D354. PubMed doi:10.1093/nar/gkp848PubMed CentralView ArticlePubMedGoogle Scholar
  11. Stetter KO, König H, Stackebrandt E. Pyrodictium gen. nov., a new genus of submarine disc-shaped sulfur reducing archaebacteria growing optimally at 105°C. Syst Appl Microbiol 1983; 4:535–551.View ArticlePubMedGoogle Scholar
  12. Fiala G, Stetter KO, Jannasch HW, Langworthy TA, Madon J. Staphylothermus marinus sp. nov. represents a novel genus of extremely thermophilic submarine heterotrophic archaebacteria growing up to 98°C. Syst Appl Microbiol 1986; 8:106–113.View ArticleGoogle Scholar
  13. Field D, Garrity G, Gray T, Morrison N, Selengut J, Sterk P, Tatusova T, Thomson N, Allen MJ, Angiuoli SV, et al. The minimum information about a genome sequence (MIGS) specification. Nat Biotechnol 2008; 26:541–547. PubMed doi:10.1038/nbt1360PubMed CentralView ArticlePubMedGoogle Scholar
  14. Woese CR, Kandler O, Wheelis ML. Towards a natural system of organisms: proposal for the domains Archaea, Bacteria, and Eucarya. Proc Natl Acad Sci USA 1990; 87:4576–4579. PubMed doi:10.1073/pnas.87.12.4576PubMed CentralView ArticlePubMedGoogle Scholar
  15. Garrity GM, Holt JG. Phylum AI. Crenarchaeota phy. nov. In Bergey’s Manual of Systematic Bacteriology, vol. 1. 2nd ed. Edited by: Garrity GM, Boone DR and Castenholz RW. Springer, New York 2001: 169–210.View ArticleGoogle Scholar
  16. List Editor. Validation of publication of new names and new combinations previously effectively published outside the IJSEM. Validation List no. 85. Int J Syst Evol Microbiol 2002; 52:685–690. PubMed doi:10.1099/ijs.0.02358-0
  17. Reysenbach AL. Class I. Thermoprotei class. nov. In Bergey’s Manual of Systematic Bacteriology, vol. 1. 2nd ed. Edited by: Garrity GM, Boone DR, and Castenholz RW. Springer, New York; 2001: 169.Google Scholar
  18. Huber H, Stetter O. Order II. Desulfurococcales ord. nov. In: Garrity GM, Boone DR, Castenholz RW (eds), Bergey’s Manual of Systematic Bacteriology, Second Edition, Volume 1, Springer, New York, 2001, p. 179–180.Google Scholar
  19. Burggraf S, Huber H, Stetter KO. Reclassification of the crenarchael orders and families in accordance with 16S rRNA sequence data. Int J Syst Bacteriol 1997; 47:657–660. PubMed doi:10.1099/00207713-47-3-657View ArticlePubMedGoogle Scholar
  20. Zillig W, Stetter KO, Prangishvilli D, Schäfer W, Wunderl S, Janekovic D, Holz I, Palm P. Desulfurococcaceae, the second family of the extremely thermophilic, anaerobic, sulfur-respiring Thermoproteales. Zentralbl Bakteriol Parasitenkd Infektioskr Hyg Abt 1 Orig 1982; 3:304–317.Google Scholar
  21. List Editor. Validation List no. 10. Validation of the publication of new names and new combinations previously effectively published outside the IJSB. Int J Syst Bacteriol 1983; 33:438–440. doi:10.1099/00207713-33-2-438
  22. List Editor. Validation List no. 22. Validation of the publication of new names and new combinations previously effectively published outside the IJSB. Int J Syst Bacteriol 1986; 36:573–576. doi:10.1099/00207713-36-4-573
  23. Ashburner M, Ball CA, Blake JA, Botstein D, Butler H, Cherry JM, Davis AP, Dolinski K, Dwight SS, Eppig JT, et al. Gene ontology: tool for the unification of biology. The Gene Ontology Consortium. Nat Genet 2000; 25:25–29. PubMed doi:10.1038/75556PubMed CentralView ArticlePubMedGoogle Scholar
  24. Zerbino DR, Birney E. Velvet: algorithms for de novo short read assembly using de Bruijn graphs. Genome Res 2008; 18:821–829. PubMed doi:10.1101/gr.074492.107PubMed CentralView ArticlePubMedGoogle Scholar
  25. Ewing B, Green P. Base-calling of automated sequencer traces using phred. II. Error probablilities. Genome Res 1998; 8:186–194. PubMedView ArticlePubMedGoogle Scholar
  26. Ewing B, Hillier L, Wendl MC, Green P. Base-calling of automated sequencer traces using phred. I. Accuracy assessment. Genome Res 1998; 8:175–185. PubMedView ArticlePubMedGoogle Scholar
  27. Gordon D, Abajian C, Green P. Consed: a graphical tool for sequence finishing. Genome Res 1998; 8:195–202. PubMedView ArticlePubMedGoogle Scholar
  28. Han C, Chain P. Finishing repeat regions automatically with Dupfinisher. In Proceedings of the 2006 international conference on bioinformatics and computational biology, ed. Arabnia HR, Valafar H. CSREA Press, 2006:141–146.
  29. Hyatt D, Chen GL, Lacascio PF, Land ML, Larimer FW, Hauser LJ. Prodigal: prokaryotic gene recognition and translation initiation site identification. BMC Bioinformatics 2010; 11:119. PubMed doi:10.1186/1471-2105-11-119PubMed CentralView ArticlePubMedGoogle Scholar
  30. Pati A, Ivanova NN, Mikhailova N, Ovchinnikova G, Hooper SD, Lykidis A, Kyrpides NC. GenePRIMP: a gene prediction improvement pipeline for prokaryotic genomes. Nat Methods 2010; 7:455–457. PubMed doi:10.1038/nmeth.1457View ArticlePubMedGoogle Scholar
  31. Lowe TM, Eddy SR. tRNAscan-SE: a program for improved detection of transfer RNA genes in genomic sequence. Nucleic Acids Res 1997; 25:955–964. PubMed doi:10.1093/nar/25.5.955PubMed CentralView ArticlePubMedGoogle Scholar
  32. INFERNAL. Inference of RNA alignments. http://infernal.janelia.org
  33. The Integrated Microbial Genomes (IMG) platform. http://img.jgi.doe.gov
  34. Markowitz VM, Mavromatis K, Ivanova NN, Chen IMA, Chu K, Kyrpides NC. IMG ER: a system for microbial genome annotation expert review and curation. Bioinformatics 2009; 25:2271–2278. PubMed doi:10.1093/bioinformatics/btp393View ArticlePubMedGoogle Scholar
  35. Silva PJ, van den Ban EC, Wassink H, Haaker H, de Castro B, Robb FT, Hagen WR. Enzymes of hydrogen metabolism in Pyrococcus furiosus. Eur J Biochem 2000; 267:6541–6551. PubMed doi:10.1046/j.1432-1327.2000.01745.xView ArticlePubMedGoogle Scholar
  36. Schut GJ, Bridger SL, Adams MWW. Insights into the metabolism of elemental sulfur by the hyperthermophilic archaeon Pyrococcus furiosus: characterization of a coenzyme A-dependent NAD(P)H sulfur oxidoreductase. J Bacteriol 2007; 189:4431–4441. PubMed doi:10.1128/JB.00031-02PubMed CentralView ArticlePubMedGoogle Scholar

Copyright

© The Author(s) 2011