4cj9
From Proteopedia
BurrH DNA-binding protein from Burkholderia rhizoxinica in its apo form
Structural highlights
Function[BAT1_MYCRK] Binds to dsDNA in a sequence-specific manner. Also binds a DNA/RNA duplex when the recognized sequence is in the DNA strand. Each tandem core repeat recognizes a single nucleotide in the target DNA via its base-specifying residue (BSR, residue 13 of each repeat); altering this amino acid changes sequence specificity.[1] [2] Publication Abstract from PubMedDNA editing offers new possibilities in synthetic biology and biomedicine for modulation or modification of cellular functions to organisms. However, inaccuracy in this process may lead to genome damage. To address this important problem, a strategy allowing specific gene modification has been achieved through the addition, removal or exchange of DNA sequences using customized proteins and the endogenous DNA-repair machinery. Therefore, the engineering of specific protein-DNA interactions in protein scaffolds is key to providing `toolkits' for precise genome modification or regulation of gene expression. In a search for putative DNA-binding domains, BurrH, a protein that recognizes a 19 bp DNA target, was identified. Here, its apo and DNA-bound crystal structures are reported, revealing a central region containing 19 repeats of a helix-loop-helix modular domain (BurrH domain; BuD), which identifies the DNA target by a single residue-to-nucleotide code, thus facilitating its redesign for gene targeting. New DNA-binding specificities have been engineered in this template, showing that BuD-derived nucleases (BuDNs) induce high levels of gene targeting in a locus of the human haemoglobin beta (HBB) gene close to mutations responsible for sickle-cell anaemia. Hence, the unique combination of high efficiency and specificity of the BuD arrays can push forward diverse genome-modification approaches for cell or organism redesign, opening new avenues for gene editing. BuD, a helix-loop-helix DNA-binding domain for genome modification.,Stella S, Molina R, Lopez-Mendez B, Juillerat A, Bertonati C, Daboussi F, Campos-Olivas R, Duchateau P, Montoya G Acta Crystallogr D Biol Crystallogr. 2014 Jul 1;70(Pt 7):2042-52. doi:, 10.1107/S1399004714011183. Epub 2014 Jun 29. PMID:25004980[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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