3N7B

SgrAI bound to secondary site DNA and Ca(II)

Summary for 3N7B

• Entry DOI: 10.2210/pdb3n7b/pdb
• Related: 3DPG 3DVO 3DW9 3MQY 3N78
• Descriptor: SgraIR restriction enzyme, DNA (5'-D(*AP*GP*TP*CP*CP*AP*CP*CP*GP*GP*GP*GP*GP*AP*CP*T)-3'), DNA (5'-D(*AP*GP*TP*CP*CP*CP*CP*CP*GP*GP*TP*GP*GP*AP*CP*T)-3'), ... (5 entities in total)
• Functional Keywords: restriction endonuclease, hydrolase-dna complex, hydrolase/dna
• Biological source: Streptomyces griseus
• Total number of polymer chains: 4
• Total formula weight: 85803.39

Authors

Horton, N.C.,Little, E.J.,Dunten, P.W. (deposition date: 2010-05-26, release date: 2010-11-24, Last modification date: 2024-02-21)

Primary citation

Little, E.J.,Dunten, P.W.,Bitinaite, J.,Horton, N.C.
New clues in the allosteric activation of DNA cleavage by SgrAI: structures of SgrAI bound to cleaved primary-site DNA and uncleaved secondary-site DNA.
Acta Crystallogr.,Sect.D, 67:67-74, 2011

PubMed Abstract: SgrAI is a type II restriction endonuclease that cuts an unusually long recognition sequence and exhibits allosteric self-activation with expansion of DNA-sequence specificity. The three-dimensional crystal structures of SgrAI bound to cleaved primary-site DNA and Mg²(+) and bound to secondary-site DNA with either Mg²(+) or Ca²(+) are presented. All three structures show a conformation of enzyme and DNA similar to the previously determined dimeric structure of SgrAI bound to uncleaved primary-site DNA and Ca²(+) [Dunten et al. (2008), Nucleic Acids Res. 36, 5405-5416], with the exception of the cleaved bond and a slight shifting of the DNA in the SgrAI/cleaved primary-site DNA/Mg²(+) structure. In addition, a new metal ion binding site is located in one of the two active sites in this structure, which is consistent with proposals for the existence of a metal-ion site near the 3'-O leaving group.

PubMed: 21206063
DOI: 10.1107/S0907444910047785

Experimental method

X-RAY DIFFRACTION (2.65 Å)