Open AccessPurification, crystallization and preliminary crystallographic analysis of KatB, a manganese catalase from Anabaena PCC 7120
Author(s) -
Bihani Subhash Chandra,
Chakravarty Dhiman,
Ballal Anand
Publication year - 2013
Publication title -
acta crystallographica section f
Language(s) - English
Resource type - Journals
ISSN - 1744-3091
DOI - 10.1107/s1744309113028017
Subject(s) - crystallography , manganese , chemistry , crystallization , anabaena , tetragonal crystal system , stereochemistry , crystal structure , biology , cyanobacteria , organic chemistry , bacteria , genetics
Catalases are enzymes that play an important role in the detoxification of hydrogen peroxide (H 2 O 2 ) in aerobic organisms. Among catalases, haem‐containing catalases are ubiquitously distributed and their enzymatic mechanism is very well understood. On the other hand, manganese catalases that contain a bimanganese core in the active site have been less well characterized and their mode of action is not fully understood. The genome of Anabaena PCC 7120 does not show the presence of a haem catalase‐like gene; instead, two ORFs encoding manganese catalases (Mn‐catalases) are present. Here, the crystallization and preliminary X‐ray crystallographic analysis of KatB, one of the two Mn‐catalases from Anabaena , are reported. KatB was crystallized using the hanging‐drop vapour‐diffusion method with PEG 400 as a precipitant and calcium acetate as an additive. Diffraction data were collected in‐house on an Agilent SuperNova system using a microfocus sealed‐tube X‐ray source. The crystal diffracted to 2.2 Å resolution at 100 K. The tetragonal crystal belonged to space group P 4 1 2 1 2 (or enantiomer), with unit‐cell parameters a = b = 101.87, c = 138.86 Å. Preliminary X‐ray diffraction analysis using the Matthews coefficient and self‐rotation function suggests the presence of a trimer in the asymmetric unit.