Crystal structure of a type II dehydroquinate dehydratase-like protein from Bifidobacterium longum.

ABSTRACT: Dehydroquinate dehydratase (DHQD) catalyzes the third step in the biosynthetic shikimate pathway. Here we identify a Bifidobacterium longum protein with high sequence homology to type II DHQDs but no detectable DHQD activity under standard assay conditions. A crystal structure reveals that the B. longum protein adopts a DHQD-like tertiary structure but a distinct quaternary state. Apparently forming a dimer, the B. longum protein lacks the active site aspartic acid contributed from a neighboring protomer in the type II DHQD dodecamer. Relating to the absence of protein-protein interactions established in the type II DHQD dodecameric assembly, substantial conformational changes distinguish the would-be active site of the B. longum protein. As B. longum possess no other genes with homology t

SUBMITTER: Light SH 

PROVIDER: S-EPMC3878977 | biostudies-literature | 2013 Mar

REPOSITORIES: biostudies-literature