Purification And Crystallographic Analysis Of A Novel Cold-Active Esterase (Haest1) From Halocynthiibacter Arcticus

This report deals with the purification, characterization, and a preliminary crystallographic study of a novel cold-active esterase (HaEst1) from Halocynthiibacter arcticus. Primary sequence analysis reveals that HaEst1 has a catalytic serine in G-x-S-x-G motif. The recombinant HaEst1 was cloned, expressed, and purified. SDS-PAGE and zymographic analysis were carried out to characterize the properties of HaEst1. A single crystal of HaEst1 was obtained in a solution containing 10% (w/v) PEG 8000/8% ethylene glycol, 0.1 M Hepes-NaOH, pH 7.5. Diffraction data were collected to 2.10 angstrom resolution with P2(1) space group. The final R-merge and R-p.i.m values were 7.6% and 3.5% for 50-2.10 angstrom resolution. The unit cell parameters were a = 35.69 angstrom, b = 91.21 angstrom, c = 79.15 angstrom, and beta = 96.9 degrees.