Summary for 1O57
| Entry DOI | 10.2210/pdb1o57/pdb |
| Descriptor | PUR OPERON REPRESSOR, SULFATE ION, 4-(2-HYDROXYETHYL)-1-PIPERAZINE ETHANESULFONIC ACID, ... (8 entities in total) |
| Functional Keywords | purine operon repressor, helix-turn-helix domain, phosphoribosyltranseferases, domain recombination, dna binding, transcription regulation, dna binding protein |
| Biological source | Bacillus subtilis |
| Total number of polymer chains | 4 |
| Total formula weight | 131254.13 |
| Authors | Sinha, S.C.,Krahn, J.,Shin, B.S.,Tomchick, D.R.,Zalkin, H.,Smith, J.L. (deposition date: 2003-04-20, release date: 2003-08-26, Last modification date: 2023-12-27) |
| Primary citation | Sinha, S.C.,Krahn, J.,Shin, B.S.,Tomchick, D.R.,Zalkin, H.,Smith, J.L. The Purine Repressor of Bacillus Subtilis: A Novel Combination of Domains Adapted for Transcription Regulation J.Bacteriol., 185:4087-4098, 2003 Cited by PubMed Abstract: The purine repressor from Bacillus subtilis, PurR, represses transcription from a number of genes with functions in the synthesis, transport, and metabolism of purines. The 2.2-A crystal structure of PurR reveals a two-domain protein organized as a dimer. The larger C-terminal domain belongs to the PRT structural family, in accord with a sequence motif for binding the inducer phosphoribosylpyrophosphate (PRPP). The PRT domain is fused to a smaller N-terminal domain that belongs to the winged-helix family of DNA binding proteins. A positively charged surface on the winged-helix domain likely binds specific DNA sequences in the recognition site. A second positively charged surface surrounds the PRPP site at the opposite end of the PurR dimer. Conserved amino acids in the sequences of PurR homologs in 21 gram-positive bacteria cluster on the proposed recognition surface of the winged-helix domain and around the PRPP binding site at the opposite end of the molecule, supporting a common function of DNA and PRPP binding for all of the proteins. The structure supports a binding mechanism in which extended regions of DNA interact with extensive protein surface. Unlike most PRT proteins, which are phosphoribosyltransferases (PRTases), PurR lacks catalytic activity. This is explained by a tyrosine side chain that blocks the site for a nucleophile cosubstrate in PRTases. Thus, B. subtilis has adapted an enzyme fold to serve as an effector-binding domain and has used it in a novel combination with the DNA-binding winged-helix domain as a repressor of purine genes. PubMed: 12837783DOI: 10.1128/JB.185.14.4087-4098.2003 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (2.2 Å) |
Structure validation
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