1YAK

Complex of Bacillus subtilis TenA with 4-amino-2-methyl-5-hydroxymethylpyrimidine

Summary for 1YAK

• Entry DOI: 10.2210/pdb1yak/pdb
• Related: 1YAD 1YAF
• Descriptor: Transcriptional activator tenA, 4-AMINO-5-HYDROXYMETHYL-2-METHYLPYRIMIDINE (3 entities in total)
• Functional Keywords: thiaminase, transcription
• Biological source: Bacillus subtilis
• Total number of polymer chains: 4
• Total formula weight: 122836.61

Authors

Toms, A.V.,Haas, A.L.,Park, J.-H.,Begley, T.P.,Ealick, S.E. (deposition date: 2004-12-17, release date: 2005-02-22, Last modification date: 2023-08-23)

Primary citation

Toms, A.V.,Haas, A.L.,Park, J.H.,Begley, T.P.,Ealick, S.E.
Structural characterization of the regulatory proteins TenA and TenI from Bacillus subtilis and identification of TenA as a thiaminase II.
Biochemistry, 44:2319-2329, 2005

PubMed Abstract: Bacillus subtilis gene products TenA and TenI have been implicated in regulating the production of extracellular proteases, but their role in the regulation process remains unclear. The structural characterization of these proteins was undertaken to help provide insight into their function. We have determined the structure of TenA alone and in complex with 4-amino-2-methyl-5-hydroxymethylpyrimidine, and we demonstrate that TenA is a thiaminase II. The TenA structure suggests that the degradation of thiamin by TenA likely proceeds via the same addition-elimination mechanism described for thiaminase I. Three active-site residues, Asp44, Cys135, and Glu205, are likely involved in substrate binding and catalysis based on the enzyme/product complex structure and the conservation of these residues within TenA sequences. We have also determined the structure of TenI. Although TenI shows significant structural homology to thiamin phosphate synthase, it has no known enzymatic function. The structure suggests that TenI is unable to bind thiamin phosphate, largely resulting from the presence of leucine at position 119, while the corresponding residue in thiamin phosphate synthase is glycine.

PubMed: 15709744
DOI: 10.1021/bi0478648

Experimental method

X-RAY DIFFRACTION (2.5 Å)