title: Solution X-ray scattering study of a full-length class A penicillin-binding protein.
abstract: Penicillin binding proteins (PBPs) catalyze essential steps in the biosynthesis of peptidoglycan, the main component of the bacterial cell wall. PBPs can harbor two catalytic domains, namely the glycosyltransferase (GT) and transpeptidase (TP) activities, the latter being the target for β-lactam antibiotics. Despite the availability of structural information regarding bi-functional PBPs, little is known regarding the interaction and flexibility between the TP and GT domains. Here, we describe the structural characterization in solution by small angle X-ray scattering (SAXS) of PBP1b, a bi-functional PBP from Streptococcus pneumoniae. The molecule is present in solution as an elongated monomer. Refinement of internal coordinates starting from a homology model yields models in which the two domains are in an extended conformation without any mutual contact compatible with the existence of restricted mobility.
authors.affiliation: Institut de Biologie Structurale, Bacterial Pathogenesis Group, UMR 5075 (CEA, CNRS, University Joseph Fourier-Grenoble I), Grenoble, France. pmache@embl.fr
authors.forename: P
authors.initials: P
authors.lastname: Macheboeuf
authors.forename: M
authors.initials: M
authors.lastname: Piuzzi
authors.forename: S
authors.initials: S
authors.lastname: Finet
authors.forename: F
authors.initials: F
authors.lastname: Bontems
authors.forename: J
authors.initials: J
authors.lastname: Pérez
authors.forename: A
authors.initials: A
authors.lastname: Dessen
authors.forename: P
authors.initials: P
authors.lastname: Vachette
mesh_terms: D008956:Models, Chemical; D046915:Penicillin-Binding Proteins / Q000737:chemistry*; D017434:Protein Structure, Tertiary; D053838:Scattering, Small Angle; D013296:Streptococcus pneumoniae / Q000378:metabolism*; D014965:X-Rays
chemical_list: D046915:Penicillin-Binding Proteins