Carboxydothermus hydrogenoformans Z-2901

Names Carboxydothermus hydrogenoformans Z-2901
Accession numbers NC_007503
Background Carboxydothermus hydrogenoformans is a hydrogenogen that was isolated from a hot spring in Kunashir Island, Russia. It belongs to the Firmicutes and grows optimally at 78 degrees Celsius. Hydrogenogens are organisms that grow anaerobically utilizing carbon monoxide (CO) as their sole carbon source and water as an electron acceptor, producing carbon dioxide and hydrogen as waste products. C.hydrogenoformans harbors a single circular chromosome. One 35-kilobase lambda-like prophage containing 50 CDS has been identified in the genome. Anaerobic species use carbon monoxide thanks to CO dehydrogenase (CODH) complexes. Five complexes have been detected in C.hydrogenoformans and have been named CODH I-V. CODH-I seems to play a role in energy conservation and CODH-III in carbon fixation. Several homologs of genes involved in sporulation in other Firmicutes have been found in C.hydrogenoformans. Among them, the master switch gene spo0A and all sporulation-specific sigma factors. Although sporulation had not been reported previously for this species, it has been shown to sporulate. Endospore-like structures were found when cultures were stressed. Of the 175 sporulation-related genes that exist in Bacillus subtilis, half have no homolog in C.hydrogenoformans. The spo0B and spo0F genes as well as many other genes involved in the protective outer layer formation, spore germination and small acid-soluble spore protein synthesis were missing. C.hydrogenoformans has been thought to be an autotroph strictly depending on CO for growth, however several aspects of its gene repertoire suggest heterotrophic capabilities. For example, it encodes transporters predicted to import various carbon compounds. It also possesses a cascade of chemotaxis genes and a complete set of flagellar genes. Chemotaxis allows microbes to respond to environmental stimuli by swimming towards nutrients (or away from toxic chemicals), which is a feature not commonly found in autotrophs. Therefore, the presence of a complete array of chemotaxis genes is consistent with its suggested heterotrophic capabilities. Thirteen two-component systems have been identified, many of which are next to transporters or oxidoreductases. C.hydrogenoformans lacks certain subfamilies of transcriptional factors that are present in its close Clostridia relatives. Its genome does not encode any protein of the LuxR family. It possesses all known components of the selenocysteine (Sec) insertion machinery and the Sec tRNA. A total of 12 selenocysteine-containing proteins have been identified. Most of them are redox proteins but two are transporters and one is a methylated-DNA-protein-cysteine methyltransferase, a suicidal DNA repair protein. Many potential cases of frameshifted genes have been identified but in absence of sequencing errors, some of them appear to be programmed frameshifts. Programmed frameshifting is a ubiquitous mechanism used to regulate translation or generate alternative protein products. (EBI Integr8)
Strain Z-2901
Complete Yes
Sequencing centre (05-OCT-2005) The Institute for Genomic Research, 9712 Medical Center Dr, Rockville, MD 20850, USA
(23-OCT-2005) National Center for Biotechnology Information, NIH, Bethesda, MD 20894, USA
Sequencing quality Level 6: Finished
Sequencing depth NA
Sequencing method NA
Isolation site "Hot swamp from Kunashir Island, Russia"
Isolation country Russia
Number of replicons 1
Gram staining properties Positive
Shape NA
Mobility Yes
Flagellar presence Yes
Number of membranes 1
Oxygen requirements Anaerobic
Optimal temperature 78.0
Temperature range Hyperthermophilic
Habitat Aquatic
Biotic relationship Free living
Host name NA
Cell arrangement NA
Sporulation NA
Metabolism NA
Energy source Chemolithotroph
Diseases NA
Pathogenicity No