title: Purification, crystallization and preliminary crystallographic analysis of the catalytic core of cystathionine β-synthase from Saccharomyces cerevisiae.
abstract: Cystathionine β-synthase (CBS; EC 4.2.1.22) catalyzes the condensation of homocysteine and serine to form cystathionine, with the release of water. In humans, deficiency in CBS activity is the most common cause of hyperhomocysteinaemia and homocystinuria. More than 160 pathogenic mutations in the human CBS gene have been described to date. Here, the purification and preliminary crystallographic analysis of the catalytic core of CBS from Saccharomyces cerevisiae (ScCBS) is described which, in contrast to other eukaryotic CBSs, lacks the N-terminal haem-binding domain and is considered to be a useful model for investigation of the pyridoxal-5'-phosphate-mediated reactions of human CBS (hCBS). The purified protein yielded two different crystal forms belonging to space groups P41212 and P212121, with unit-cell parameters a = b = 72.390, c = 386.794 Å and a = 58.156, b = 89.988, c = 121.687 Å, respectively. Diffraction data were collected to 2.7 and 3.1 Å resolution, respectively, using synchrotron radiation. Preliminary analysis of the X-ray data suggests the presence of ScCBS homodimers in both types of crystals.
authors.affiliation: Structural Biology Unit, CIC bioGUNE, Parque Tecnológico de Bizkaia, Edificio 800, 48160 Derio, Bizkaia , Spain.
authors.forename: June
authors.initials: J
authors.lastname: Ereño-Orbea
authors.affiliation: Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO 80045, USA.
authors.forename: Tomas
authors.initials: T
authors.lastname: Majtan
authors.affiliation: Structural Biology Unit, CIC bioGUNE, Parque Tecnológico de Bizkaia, Edificio 800, 48160 Derio, Bizkaia , Spain.
authors.forename: Iker
authors.initials: I
authors.lastname: Oyenarte
authors.affiliation: Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO 80045, USA.
authors.forename: Jan P
authors.initials: JP
authors.lastname: Kraus
authors.affiliation: Structural Biology Unit, CIC bioGUNE, Parque Tecnológico de Bizkaia, Edificio 800, 48160 Derio, Bizkaia , Spain.
authors.forename: Luis Alfonso
authors.initials: LA
authors.lastname: Martínez-Cruz
mesh_terms: D020134:Catalytic Domain; D002846:Chromatography, Affinity; D003460:Crystallization; D018360:Crystallography, X-Ray; D003541:Cystathionine beta-Synthase / Q000737:chemistry* / Q000302:isolation & purification; D012441:Saccharomyces cerevisiae / Q000201:enzymology*; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry* / Q000302:isolation & purification
chemical_list: D029701:Saccharomyces cerevisiae Proteins; D003541:Cystathionine beta-Synthase
keywords: CBS domain; S-adenosylmethionine; cystathionine β-synthase; cysteine biosynthesis; homocysteine; pyridoxal-5′-phosphate; transsulfuration pathway