Expression, crystallization and preliminary X-ray crystallographic analysis of cystathionine β-lyase from Acinetobacter baumannii OXA-23

Multidrug‐resistant Acinetobacter baumannii (Ab) has emerged as a leading nosocomial pathogen because of its resistance to most currently available antibiotics. Cystathionine β‐lyase (CBL), a pyridoxal 5′‐phosphate (PLP)‐dependent enzyme, catalyzes the second step in the transsulfuration pathway, which is essential for the metabolic interconversion of the sulfur‐containing amino acids homocysteine and methionine. The enzymes of the transsulfuration pathway are considered to be attractive drug targets owing to their specificity to microbes and plants. As a potential target for the development of novel antibacterial drugs, the AbCBL protein was expressed, purified and crystallized. An AbCBL crystal diffracted to 1.57 Å resolution and belonged to the trigonal space group P3112, with unit‐cell parameters a = b = 102.9, c = 136.5 Å. The asymmetric unit contained two monomers, with a corresponding VM of 2.3 Å3 Da−1 and a solvent content of 46.9%.