Summary information and primary citation
- PDB-id
-
1d02;
DSSR-derived features in text and
JSON formats; DNAproDB
- Class
- hydrolase-DNA
- Method
- X-ray (1.7 Å)
- Summary
- Crystal structure of muni restriction endonuclease in
complex with cognate DNA
- Reference
-
Deibert M, Grazulis S, Janulaitis A, Siksnys V, Huber R
(1999): "Crystal
structure of MunI restriction endonuclease in complex
with cognate DNA at 1.7 A resolution." EMBO
J., 18, 5805-5816. doi: 10.1093/emboj/18.21.5805.
- Abstract
- The MunI restriction enzyme recognizes the palindromic
hexanucleotide sequence C/AATTG (the '/' indicates the
cleavage site). The crystal structure of its active site
mutant D83A bound to cognate DNA has been determined at 1.7
A resolution. Base-specific contacts between MunI and DNA
occur exclusively in the major groove. While DNA-binding
sites of most other restriction enzymes are comprised of
discontinuous sequence segments, MunI combines all residues
involved in the base-specific contacts within one short
stretch (residues R115-R121) located at the N-terminal
region of the 3(10)4 helix. The outer CG base pair of the
recognition sequence is recognized solely by R115 through
hydrogen bonds made by backbone and side chain atoms to
both bases. The mechanism of recognition of the central
AATT nucleotides by MunI is similar to that of EcoRI, which
recognizes the G/AATTC sequence. The local conformation of
AATT deviates from the typical B-DNA form and is remarkably
similar to EcoRI-DNA. It appears to be essential for
specific hydrogen bonding and recognition by MunI and
EcoRI.
