1tht
STRUCTURE OF A MYRISTOYL-ACP-SPECIFIC THIOESTERASE FROM VIBRIO HARVEYISTRUCTURE OF A MYRISTOYL-ACP-SPECIFIC THIOESTERASE FROM VIBRIO HARVEYI
Structural highlights
Function[LUXD_VIBHA] Acyl transferase is part of the fatty acid reductase system required for aldehyde biosynthesis; it produces fatty acids for the luminescent reaction. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe crystal structure of a myristoyl acyl carrier protein specific thioesterase (C14ACP-TE) from a bioluminescent bacterium, Vibrio harveyi, was solved by multiple isomorphous replacement methods and refined to an R factor of 22% at 2.1-A resolution. This is the first elucidation of a three-dimensional structure of a thioesterase. The overall tertiary architecture of the enzyme resembles closely the consensus fold of the rapidly expanding superfamily of alpha/beta hydrolases, although there is no detectable homology with any of its members at the amino acid sequence level. Particularly striking similarity exists between the C14ACP-TE structure and that of haloalkane dehalogenase from Xanthobacter autotrophicus. Contrary to the conclusions of earlier studies [Ferri, S. R., & Meighen, E. A. (1991) J. Biol. Chem. 266, 12852-12857] which implicated Ser77 in catalysis, the crystal structure of C14ACP-TE reveals a lipase-like catalytic triad made up of Ser114, His241, and Asp211. Surprisingly, the gamma-turn with Ser114 in a strained secondary conformation (phi = 53 degrees, psi = -127 degrees), characteristic of the so-called nucleophilic elbow, does not conform to the frequently invoked lipase/esterase consensus sequence (Gly-X-Ser-X-Gly), as the positions of both glycines are occupied by larger amino acids. Site-directed mutagenesis and radioactive labeling support the catalytic function of Ser114. Crystallographic analysis of the Ser77-->Gly mutant at 2.5-A resolution revealed no structural changes; in both cases the loop containing the residue in position 77 is disordered.(ABSTRACT TRUNCATED AT 250 WORDS) Structure of a myristoyl-ACP-specific thioesterase from Vibrio harveyi.,Lawson DM, Derewenda U, Serre L, Ferri S, Szittner R, Wei Y, Meighen EA, Derewenda ZS Biochemistry. 1994 Aug 16;33(32):9382-8. PMID:8068614[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences |
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