4X8Q
X-ray crystal structure of AlkD2 from Streptococcus mutans
Summary for 4X8Q
| Entry DOI | 10.2210/pdb4x8q/pdb |
| Descriptor | Uncharacterized protein, PHOSPHATE ION, GLYCEROL, ... (6 entities in total) |
| Functional Keywords | unknown function, heat repeat, alk motif |
| Biological source | Streptococcus mutans |
| Total number of polymer chains | 1 |
| Total formula weight | 25039.99 |
| Authors | Mullins, E.A.,Shi, R.,Eichman, B.F. (deposition date: 2014-12-10, release date: 2015-05-27, Last modification date: 2023-09-27) |
| Primary citation | Mullins, E.A.,Shi, R.,Kotsch, L.A.,Eichman, B.F. A New Family of HEAT-Like Repeat Proteins Lacking a Critical Substrate Recognition Motif Present in Related DNA Glycosylases. Plos One, 10:e0127733-e0127733, 2015 Cited by PubMed Abstract: DNA glycosylases are important repair enzymes that eliminate a diverse array of aberrant nucleobases from the genomes of all organisms. Individual bacterial species often contain multiple paralogs of a particular glycosylase, yet the molecular and functional distinctions between these paralogs are not well understood. The recently discovered HEAT-like repeat (HLR) DNA glycosylases are distributed across all domains of life and are distinct in their specificity for cationic alkylpurines and mechanism of damage recognition. Here, we describe a number of phylogenetically diverse bacterial species with two orthologs of the HLR DNA glycosylase AlkD. One ortholog, which we designate AlkD2, is substantially less conserved. The crystal structure of Streptococcus mutans AlkD2 is remarkably similar to AlkD but lacks the only helix present in AlkD that penetrates the DNA minor groove. We show that AlkD2 possesses only weak DNA binding affinity and lacks alkylpurine excision activity. Mutational analysis of residues along this DNA binding helix in AlkD substantially reduced binding affinity for damaged DNA, for the first time revealing the importance of this structural motif for damage recognition by HLR glycosylases. PubMed: 25978435DOI: 10.1371/journal.pone.0127733 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (1.729 Å) |
Structure validation
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