'''Crystal structure of E. coli Lysophospholiase L1/Acyl-CoA Thioesterase I/Protease I L109P mutant'''
===Crystal structure of E. coli Lysophospholiase L1/Acyl-CoA Thioesterase I/Protease I L109P mutant===
==Overview==
<!--
Escherichia coli thioesterase I (TAP) is a multifunctional enzyme possessing activities of thioesterase, esterase, arylesterase, protease, and lysophospholipase. In particular, TAP has stereoselectivity for amino acid derivative substrates, hence it is useful for the kinetic resolution of racemic mixtures of industrial chemicals. In the present work, the crystal structure of native TAP was determined at 1.9A, revealing a minimal SGNH-hydrolase fold. The structure of TAP in complex with a diethyl phosphono moiety (DEP) identified its catalytic triad, Ser10-Asp154-His157, and oxyanion hole, Ser10-Gly44-Asn73. The oxyanion hole of TAP consists of three residues each separated from the other by more than 3.5A, implying that all of them are highly polarized when substrate bound. The catalytic (His)C(epsilon1)-H...O=C hydrogen bond usually plays a role in the catalytic mechanisms of most serine hydrolases, however, there were none present in SGNH-hydrolases. We propose that the existence of the highly polarized tri-residue-constituted oxyanion hole compensates for the lack of a (His)C(epsilon1)-H...O=C hydrogen bond. This suggests that members of the SGNH-hydrolase family may employ a unique catalytic mechanism. In addition, most SGNH-hydrolases have low sequence identities and presently there is no clear criterion to define consensus sequence blocks. Through comparison of TAP and the three SGNH-hydrolase structures currently known, we have identified a unique hydrogen bond network which stabilizes the catalytic center: a newly discovered structural feature of SGNH-hydrolases. We have defined these consensus sequence blocks providing a basis for the sub-classification of SGNH-hydrolases.
The line below this paragraph, {{ABSTRACT_PUBMED_12842470}}, adds the Publication Abstract to the page
(as it appears on PubMed at http://www.pubmed.gov), where 12842470 is the PubMed ID number.
-->
{{ABSTRACT_PUBMED_12842470}}
==About this Structure==
==About this Structure==
Line 28:
Line 32:
[[Category: Hydrolase]]
[[Category: Hydrolase]]
[[Category: Protease]]
[[Category: Protease]]
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Fri May 2 21:45:43 2008''
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Tue Jul 1 20:41:46 2008''
Revision as of 20:41, 1 July 2008
This article has been automatically seeded. Changes to this page should pertain to the PDB entry only and not to the protein or biomolecule in general.
Crystal structure of E. coli Lysophospholiase L1/Acyl-CoA Thioesterase I/Protease I L109P mutantCrystal structure of E. coli Lysophospholiase L1/Acyl-CoA Thioesterase I/Protease I L109P mutant
Crystal structure of Escherichia coli thioesterase I/protease I/lysophospholipase L1: consensus sequence blocks constitute the catalytic center of SGNH-hydrolases through a conserved hydrogen bond network., Lo YC, Lin SC, Shaw JF, Liaw YC, J Mol Biol. 2003 Jul 11;330(3):539-51. PMID:12842470
