Crystallization and preliminary X-ray diffraction analysis ofHypocrea jecorinaCel7A in two new crystal forms

Abstract

Cel7A (previously known as cellobiohydrolase I) fromHypocrea jecorinawas crystallized in two crystalline forms, neither of which have been previously reported. Both forms co-crystallize under the same crystallization conditions. The first crystal form belonged to space groupC2, with unit-cell parametersa= 152.5,b= 44.9,c= 57.6 Å, β = 101.2°, and diffracted X-rays to 1.5 Å resolution. The second crystal form belonged to space groupP6322, with unit-cell parametersa=b≃ 155,c≃ 138 Å, and diffracted X-rays to 2.5 Å resolution. The crystals were obtained using full-length Cel7A, which consists of a large 434-residue N-terminal catalytic domain capable of cleaving cellulose, a 27-residue flexible linker and a small 36-residue C-terminal carbohydrate-binding module (CBM). However, a preliminary analysis of the electron-density maps suggests that the linker and CBM are disordered in both crystal forms. Complete refinement and structure analysis are currently in progress.