%0 Journal Article %A NÖLLING, JÖRK %A ELFNER, AMY %A PALMER, JOHN R. %A STEIGERWALD, VANESSA J. %A PIHL, TODD D. %A LAKE, JAMES A. %A REEVE, JOHN N. %T NOTES: Phylogeny of Methanopyrus kandleri Based on Methyl Coenzyme M Reductase Operons %D 1996 %J International Journal of Systematic and Evolutionary Microbiology, %V 46 %N 4 %P 1170-1173 %@ 1466-5034 %R https://doi.org/10.1099/00207713-46-4-1170 %I Microbiology Society, %X The mcrBDCGA operon that encodes methyl coenzyme M reductase (MR) in the hyperthermophile Methanopyrus kandleri was cloned and sequenced. The results of a phylogenetic analysis of the nine MR sequences now available support the position that M. kandleri is a separate methanogen lineage. As in other methanogens, the M. kandleri mcr operon is located immediately upstream of the mtrE gene, the promoter-proximal gene in an operon that encodes the N 5-methyltetrahydromethanopterin:coenzyme M methyltransferase that catalyzes the step preceding the MR-catalyzed reaction in methanogenesis. In contrast to other methanogens and hyperthermophilic members of the Archaea. CG dinucleotides and CG-containing codons occur frequently in M. kandleri DNA. The MR subunit-encoding genes are preceded by sequences consistent with ribosome binding sites, indicating that mRNA-rRNA base pairing can still direct translation initiation in cells growing at temperatures above 100°C. %U https://www.microbiologyresearch.org/content/journal/ijsem/10.1099/00207713-46-4-1170