Structure and stereospecificity of the dehydratase domain from the terminal module of the rifamycin polyketide synthase.

ABSTRACT: RifDH10, the dehydratase domain from the terminal module of the rifamycin polyketide synthase, catalyzes the stereospecific syn dehydration of the model substrate (2S,3S)-2-methyl-3-hydroxypentanoyl-RifACP10, resulting in the exclusive formation of (E)-2-methyl-2-pentenoyl-RifACP10. RifDH10 does not dehydrate any of the other three diastereomeric, RifACP10-bound, diketide thioester substrates. On the other hand, when EryACP6, from the sixth module of the erythromycin polyketide synthase, is substituted for RifACP10, RifDH10 stereospecifically dehydrates only (2R,3R)-2-methyl-3-hydroxypentanoyl-EryACP6 to give exclusively (E)-2-methyl-2-pentenoyl-EryACP6, with no detectable dehydration of any of the other three diastereomeric, EryACP6-bound, diketides. An identical alteration in substrate d

SUBMITTER: Gay D 

PROVIDER: S-EPMC3948214 | biostudies-literature | 2013 Dec

REPOSITORIES: biostudies-literature