1SA3

An asymmetric complex of restriction endonuclease MspI on its palindromic DNA recognition site

Summary for 1SA3

• Entry DOI: 10.2210/pdb1sa3/pdb
• Descriptor: 5'-D(*CP*CP*CP*CP*CP*GP*GP*GP*GP*G)-3', Type II restriction enzyme MspI, SODIUM ION, ... (4 entities in total)
• Functional Keywords: protein-dna complex, hydrolase-dna complex, hydrolase/dna
• Biological source: Moraxella sp.
• Total number of polymer chains: 6
• Total formula weight: 71985.92

Authors

Xu, Q.S.,Kucera, R.B.,Roberts, R.J.,Guo, H.C. (deposition date: 2004-02-06, release date: 2004-09-07, Last modification date: 2024-02-14)

Primary citation

Xu, Q.S.,Kucera, R.B.,Roberts, R.J.,Guo, H.C.
An Asymmetric Complex of Restriction Endonuclease MspI on Its Palindromic DNA Recognition Site.
STRUCTURE, 12:1741-1747, 2004

PubMed Abstract: Most well-known restriction endonucleases recognize palindromic DNA sequences and are classified as Type IIP. Due to the recognition and cleavage symmetry, Type IIP enzymes are usually found to act as homodimers in forming 2-fold symmetric enzyme-DNA complexes. Here we report an asymmetric complex of the Type IIP restriction enzyme MspI in complex with its cognate recognition sequence. Unlike any other Type IIP enzyme reported to date, an MspI monomer and not a dimer binds to a palindromic DNA sequence. The enzyme makes specific contacts with all 4 base pairs in the recognition sequence, by six direct and five water-mediated hydrogen bonds and numerous van der Waal contacts. This MspI-DNA structure represents the first example of asymmetric recognition of a palindromic DNA sequence by two different structural motifs in one polypeptide. A few possible pathways are discussed for MspI to cut both strands of DNA, either as a monomer or dimer.

PubMed: 15341737
DOI: 10.1016/j.str.2004.07.014

Experimental method

X-RAY DIFFRACTION (1.95 Å)