title: Staphylococcus aureus thiaminase II: oligomerization warrants proteolytic protection against serine proteases.
abstract: Staphylococcus aureus TenA (SaTenA) is a thiaminase type II enzyme that catalyzes the deamination of aminopyrimidine, as well as the cleavage of thiamine into 4-amino-5-hydroxymethyl-2-methylpyrimidine (HMP) and 5-(2-hydroxyethyl)-4-methylthiazole (THZ), within thiamine (vitamin B1) metabolism. Further, by analogy with studies of Bacillus subtilis TenA, SaTenA may act as a regulator controlling the secretion of extracellular proteases such as the subtilisin type of enzymes in bacteria. Thiamine biosynthesis has been identified as a potential drug target of the multi-resistant pathogen S. aureus and therefore all enzymes involved in the S. aureus thiamine pathway are presently being investigated in detail. Here, the structure of SaTenA, determined by molecular replacement and refined at 2.7 Å resolution to an R factor of 21.6% with one homotetramer in the asymmetric unit in the orthorhombic space group P212121, is presented. The tetrameric state of wild-type (WT) SaTenA was postulated to be the functional biological unit and was confirmed by small-angle X-ray scattering (SAXS) experiments in solution. To obtain insights into structural and functional features of the oligomeric SaTenA, comparative kinetic investigations as well as experiments analyzing the structural stability of the WT SaTenA tetramer versus a monomeric SaTenA mutant were performed.
authors: Laboratory for Structural Biology of Infection and Inflammation, University of Hamburg, c/o DESY, Notkestrasse 85, Building 22A, 22603 Hamburg, Germany.
authors: Afshan
authors: A
authors: Begum
authors: Julia
authors: J
authors: Drebes
authors: Alexey
authors: A
authors: Kikhney
authors: Ingrid B
authors: IB
authors: Müller
authors: Markus
authors: M
authors: Perbandt
authors: Dmitri
authors: D
authors: Svergun
authors: Carsten
authors: C
authors: Wrenger
authors: Christian
authors: C
authors: Betzel
mesh_terms: D006801:Humans; D006867:Hydrolases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D008958:Models, Molecular; D016297:Mutagenesis, Site-Directed; D011487:Protein Conformation; D055503:Protein Multimerization; D059748:Proteolysis; D057057:Serine Proteases / Q000378:metabolism; D013203:Staphylococcal Infections / Q000201:enzymology / Q000382:microbiology*; D013211:Staphylococcus aureus / Q000737:chemistry / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D020860:Subtilisin / Q000378:metabolism; D013831:Thiamine / Q000378:metabolism; D014357:Trypsin / Q000378:metabolism
chemical_list: D006867:Hydrolases; D057057:Serine Proteases; D014357:Trypsin; D020860:Subtilisin; C022731:thiaminase II; D013831:Thiamine
keywords: proteolytic stability; thiaminases; thiamine; transcriptional activators; vitamin B1