title: Functional analysis of substrate and cofactor complex structures of a thymidylate synthase-complementing protein.
abstract: Like thymidylate synthase (TS) in eukaryotes, the thymidylate synthase-complementing proteins (TSCPs) are mandatory for cell survival of many prokaryotes in the absence of external sources of thymidylate. Details of the mechanism of this novel family of enzymes are unknown. Here, we report the structural and functional analysis of a TSCP from Thermotoga maritima and its complexes with substrate, analogs, and cofactor. The structures presented here provide a basis for rationalizing the TSCP catalysis and reveal the possibility of the design of an inhibitor. We have identified a new helix-loop-strand FAD binding motif characteristic of the enzymes in the TSCP family. The presence of a hydrophobic core with residues conserved among the TSCP family suggests a common overall fold.
authors.affiliation: Stanford Synchrotron Radiation Laboratory, Stanford University, 2575 Sand Hill Road, SSRL MS 69, Menlo Park, CA 94025, USA. iimathew@stanford.edu
authors.forename: Irimpan I
authors.initials: II
authors.lastname: Mathews
authors.forename: Ashley M
authors.initials: AM
authors.lastname: Deacon
authors.forename: Jaume M
authors.initials: JM
authors.lastname: Canaves
authors.forename: Daniel
authors.initials: D
authors.lastname: McMullan
authors.forename: Scott A
authors.initials: SA
authors.lastname: Lesley
authors.forename: Sanjay
authors.initials: S
authors.lastname: Agarwalla
authors.forename: Peter
authors.initials: P
authors.lastname: Kuhn
mesh_terms: D000595:Amino Acid Sequence; D000900:Anti-Bacterial Agents / Q000737:chemistry; D001424:Bacterial Infections / Q000453:epidemiology; D001426:Bacterial Proteins / Q000737:chemistry* / Q000378:metabolism; D001665:Binding Sites; D018360:Crystallography, X-Ray; D003856:Deoxyuracil Nucleotides / Q000378:metabolism; D005182:Flavin-Adenine Dinucleotide / Q000378:metabolism; D046911:Macromolecular Substances; D008958:Models, Molecular; D008969:Molecular Sequence Data; D015394:Molecular Structure; D017510:Protein Folding; D017434:Protein Structure, Tertiary; D020124:Thermotoga maritima / Q000201:enzymology*; D013940:Thymidylate Synthase / Q000737:chemistry* / Q000378:metabolism*
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D003856:Deoxyuracil Nucleotides; D046911:Macromolecular Substances; D005182:Flavin-Adenine Dinucleotide; C007267:2'-deoxyuridylic acid; D013940:Thymidylate Synthase