Structure of an aryl esterase from Pseudomonas fluorescens.
The structure of PFE, an aryl esterase from Pseudomonas fluorescens, has been solved to a resolution of 1.8 A by X-ray diffraction and shows a characteristic alpha/beta-hydrolase fold. In addition to catalyzing the hydrolysis of esters in vitro, PFE also shows low bromoperoxidase activity. PFE shows highest structural similarity, including the active-site environment, to a family of non-heme bacterial haloperoxidases, with an r.m.s. deviation in 271 C(alpha) atoms between PFE and its five closest structural neighbors averaging 0.8 A. PFE has far less similarity (r.m.s. deviation in 218 C(alpha) atoms of 5.0 A) to P. fluorescens carboxyl esterase. PFE favors activated esters with small acyl groups, such as phenyl acetate. The X-ray structure of PFE reveals a significantly occluded active site. In addition, several residues, including Trp28 and Met95, limit the size of the acyl-binding pocket, explaining its preference for small acyl groups.
Cheeseman
Jeremy D
JD
Department of Chemistry, McGill University, 801 Sherbrooke Street West, Montreál, Québec H3A 2K6, Canada.
Tocilj
Ante
A
Park
Seongsoon
S
Schrag
Joseph D
JD
Kazlauskas
Romas J
RJ
D001665:Binding Sites; D002265:Carboxylic Ester Hydrolases / Q000737:chemistry* / Q000378:metabolism; D003460:Crystallization; D018360:Crystallography, X-Ray; D006868:Hydrolysis; D008958:Models, Molecular; D017434:Protein Structure, Tertiary; D011551:Pseudomonas fluorescens / Q000201:enzymology*; D013237:Stereoisomerism; D013912:Threonine / Q000378:metabolism
D013912:Threonine; D002265:Carboxylic Ester Hydrolases; C019734:arylesterase