title: Crystallization and preliminary X-ray diffraction analysis of the lytic transglycosylase MltE from Escherichia coli.
abstract: MltE from Escherichia coli (193 amino acids, 21,380 Da) is a lytic transglycosylase that initiates the first step of cell-wall recycling. This enzyme is responsible for the cleavage of the cell-wall peptidoglycan at the β-1,4-glycosidic bond between the N-acetylglucosamine and N-acetylmuramic acid units. At the end this reaction generates a disaccharide that is internalized and initiates the recycling process. To obtain insights into the biological functions of MltE, crystallization trials were performed and crystals of MltE protein that were suitable for X-ray diffraction analysis were obtained. The MltE protein of E. coli was crystallized using the hanging-drop vapour-diffusion method at 291 K. Crystals grew from a mixture consisting of 28% polyethylene glycol 4000, 0.1 M Tris pH 8.4 and 0.2 M magnesium chloride. Further optimization was performed using the microbatch technique. Single crystals were obtained that belonged to the orthorhombic space group C222(1), with unit-cell parameters a=123.32, b=183.93, c=35.29 Å, and diffracted to a resolution of 2.1 Å.
authors.affiliation: Department of Crystallography and Structural Biology, Instituto de Química-Física Rocasolano, Consejo Superior de Investigaciones Científicas, Serrano 119, Madrid 28006, Spain.
authors.forename: Cecilia
authors.initials: C
authors.lastname: Artola-Recolons
authors.forename: Leticia I
authors.initials: LI
authors.lastname: Llarrull
authors.forename: Elena
authors.initials: E
authors.lastname: Lastochkin
authors.forename: Shahriar
authors.initials: S
authors.lastname: Mobashery
authors.forename: Juan A
authors.initials: JA
authors.lastname: Hermoso
mesh_terms: D003460:Crystallization; D018360:Crystallography, X-Ray; D004926:Escherichia coli / Q000201:enzymology*; D029968:Escherichia coli Proteins / Q000737:chemistry* / Q000302:isolation & purification; D016695:Glycosyltransferases / Q000737:chemistry* / Q000302:isolation & purification; D008969:Molecular Sequence Data; D011487:Protein Conformation
chemical_list: D029968:Escherichia coli Proteins; D016695:Glycosyltransferases; C578387:MltE protein, E coli