Download MendeleyStructure and Functional Analysis of RifR, the Type II Thioesterase from the Rifamycin Biosynthetic Pathway.
Claxton, H.B., Akey, D.L., Silver, M.K., Admiraal, S.J., Smith, J.L.(2009) J Biol Chem 284: 5021-5029
- PubMed: 19103602
- DOI: https://doi.org/10.1074/jbc.M808604200
- Primary Citation of Related Structures:
3FLA, 3FLB - PubMed Abstract:
Two thioesterases are commonly found in natural product biosynthetic clusters, a type I thioesterase that is responsible for removing the final product from the biosynthetic complex and a type II thioesterase that is believed to perform housekeeping functions such as removing aberrant units from carrier domains. We present the crystal structure and the kinetic analysis of RifR, a type II thioesterase from the hybrid nonribosomal peptide synthetases/polyketide synthase rifamycin biosynthetic cluster of Amycolatopsis mediterranei. Steady-state kinetics show that RifR has a preference for the hydrolysis of acyl units from the phosphopantetheinyl arm of the acyl carrier domain over the hydrolysis of acyl units from the phosphopantetheinyl arm of acyl-CoAs as well as a modest preference for the decarboxylated substrate mimics acetyl-CoA and propionyl-CoA over malonyl-CoA and methylmalonyl-CoA. Multiple RifR conformations and structural similarities to other thioesterases suggest that movement of a helical lid controls access of substrates to the active site of RifR.
Organizational Affiliation:
Life Science Institute, University of Michigan, Ann Arbor, Michigan 48109, USA.
