3I6Y

Structure of an esterase from the oil-degrading bacterium Oleispira antarctica

Summary for 3I6Y

• Entry DOI: 10.2210/pdb3i6y/pdb
• Descriptor: Esterase APC40077, CHLORIDE ION, 1,2-ETHANEDIOL, ... (5 entities in total)
• Functional Keywords: oleispira antarctica, lipase, structural genomics, psi-2, protein structure initiative, midwest center for structural genomics, mcsg, hydrolase
• Biological source: Oleispira antarctica
• Total number of polymer chains: 2
• Total formula weight: 63336.97

Authors

Singer, A.U.,Evdokimova, E.,Kagan, O.,Edwards, A.M.,Joachimiak, A.,Savchenko, A.,Midwest Center for Structural Genomics (MCSG) (deposition date: 2009-07-07, release date: 2009-07-28, Last modification date: 2024-10-16)

Primary citation

Lemak, S.,Tchigvintsev, A.,Petit, P.,Flick, R.,Singer, A.U.,Brown, G.,Evdokimova, E.,Egorova, O.,Gonzalez, C.F.,Chernikova, T.N.,Yakimov, M.M.,Kube, M.,Reinhardt, R.,Golyshin, P.N.,Savchenko, A.,Yakunin, A.F.
Structure and activity of the cold-active and anion-activated carboxyl esterase OLEI01171 from the oil-degrading marine bacterium Oleispira antarctica.
Biochem.J., 445:193-203, 2012

PubMed Abstract: The uncharacterized α/β-hydrolase protein OLEI01171 from the psychrophilic marine bacterium Oleispira antarctica belongs to the PF00756 family of putative esterases, which also includes human esterase D. In the present paper we show that purified recombinant OLEI01171 exhibits high esterase activity against the model esterase substrate α-naphthyl acetate at 5-30°C with maximal activity at 15-20°C. The esterase activity of OLEI01171 was stimulated 3-8-fold by the addition of chloride or several other anions (0.1-1.0 M). Compared with mesophilic PF00756 esterases, OLEI01171 exhibited a lower overall protein thermostability. Two crystal structures of OLEI01171 were solved at 1.75 and 2.1 Å resolution and revealed a classical serine hydrolase catalytic triad and the presence of a chloride or bromide ion bound in the active site close to the catalytic Ser148. Both anions were found to co-ordinate a potential catalytic water molecule located in the vicinity of the catalytic triad His257. The results of the present study suggest that the bound anion perhaps contributes to the polarization of the catalytic water molecule and increases the rate of the hydrolysis of an acyl-enzyme intermediate. Alanine replacement mutagenesis of OLEI01171 identified ten amino acid residues important for esterase activity. The replacement of Asn225 by lysine had no significant effect on the activity or thermostability of OLEI01171, but resulted in a detectable increase of activity at 35-45°C. The present study has provided insight into the molecular mechanisms of activity of a cold-active and anion-activated carboxyl esterase.

PubMed: 22519667
DOI: 10.1042/BJ20112113

Experimental method

X-RAY DIFFRACTION (1.75 Å)