title: A 3-hydroxy-3-methylglutaryl-CoA lyase gene in the photosynthetic bacterium Rhodospirillum rubrum.
abstract: A 1.2 kb long DNA segment from Rhodospirillum rubrum has been sequenced (EMBL/GenBank accession number: U41280). This DNA segment includes the first sequenced gene for a putative 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) lyase, termed hmgL, from a photosynthetic organism. The sequenced segment also contains a ribosome-binding site and two clusters of possible-35 and -10 promotor sequences preceding the hmgL gene. Translation of the gene would yield a 303 amino-acid-long protein with a calculated molecular weight of 31.1 kDa. This protein shows 55-60% identity and approx. 75% similarity, including conservative substitutions, with the three eukaryotic and the single prokaryotic HMG-CoA lyases which previously have been sequenced. The R. rubrum enzyme showed stronger homology to the chicken HMG-CoA lyase than to the other bacterial protein. Significant sequence similarity was also found with homocitrate synthases from nitrogen-fixing prokaryotes. In contrast to the other sequenced prokaryotic HMG-CoA lyase (from Pseudomonas mevalonii), the R. rubrum hmgL does not seem to appear in an operon together with a HMG-CoA reductase. The hmgL gene was transcribed in photosynthetically grown cells as judged by amplification of cDNAs synthesised from DNA-free total RNA. In addition, HMG-CoA lyase activity was found in R. rubrum cells grown anaerobically in the light with leucine as the carbon source.
authors.affiliation: Institutionen för biokemi, Arrheniuslaboratorierna för naturvetenskap, Stockholms universitet, Sweden.
authors.forename: M
authors.initials: M
authors.lastname: Baltscheffsky
authors.forename: M
authors.initials: M
authors.lastname: Brosché
authors.forename: T
authors.initials: T
authors.lastname: Hultman
authors.forename: L
authors.initials: L
authors.lastname: Lundvik
authors.forename: P
authors.initials: P
authors.lastname: Nyrén
authors.forename: Y
authors.initials: Y
authors.lastname: Sakai-Nore
authors.forename: A
authors.initials: A
authors.lastname: Severin
authors.forename: A
authors.initials: A
authors.lastname: Strid
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D005798:Genes, Bacterial; D008969:Molecular Sequence Data; D009876:Operon; D007652:Oxo-Acid-Lyases / Q000145:classification / Q000235:genetics* / Q000378:metabolism; D010788:Photosynthesis; D010802:Phylogeny; D011401:Promoter Regions, Genetic; D012329:RNA, Bacterial / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics; D012247:Rhodospirillum rubrum / Q000201:enzymology / Q000235:genetics*; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D013728:Terminator Regions, Genetic; D014158:Transcription, Genetic
chemical_list: D012329:RNA, Bacterial; D012333:RNA, Messenger; D007652:Oxo-Acid-Lyases; C021410:3-hydroxy-3-methylglutaryl-coenzyme A lyase