Methanogen homoaconitase catalyzes both hydrolyase reactions in coenzyme B biosynthesis.

ABSTRACT: Homoaconitase enzymes catalyze hydrolyase reactions in the alpha-aminoadipate pathway for lysine biosynthesis or the 2-oxosuberate pathway for methanogenic coenzyme B biosynthesis. Despite the homology of this iron-sulfur protein to aconitase, previously studied homoaconitases catalyze only the hydration of cis-homoaconitate to form homoisocitrate rather than the complete isomerization of homocitrate to homoisocitrate. The MJ1003 and MJ1271 proteins from the methanogen Methanocaldococcus jannaschii formed the first homoaconitase shown to catalyze both the dehydration of (R)-homocitrate to form cis-homoaconitate, and its hydration is shown to produce homoisocitrate. This heterotetrameric enzyme also used the analogous longer chain substrates cis-(homo)(2)aconitate, cis-(homo)(3)aconitate, a

SUBMITTER: Drevland RM 

PROVIDER: S-EPMC2662002 | biostudies-literature | 2008 Oct

REPOSITORIES: biostudies-literature