2IXS

Structure of SdaI restriction endonuclease

Summary for 2IXS

• Entry DOI: 10.2210/pdb2ixs/pdb
• Descriptor: SDAI RESTRICTION ENDONUCLEASE, SULFATE ION, 4-(2-HYDROXYETHYL)-1-PIPERAZINE ETHANESULFONIC ACID, ... (5 entities in total)
• Functional Keywords: restriction endonuclease, sdai, hydrolase, endonuclease, domain architecture
• Biological source: STREPTOMYCES DIASTATICUS
• Total number of polymer chains: 2
• Total formula weight: 74638.02

Authors

Tamulaitiene, G.,Jakubauskas, A.,Urbanke, C.,Huber, R.,Grazulis, S.,Siksnys, V. (deposition date: 2006-07-11, release date: 2006-09-14, Last modification date: 2024-05-08)

Primary citation

Tamulaitiene, G.,Jakubauskas, A.,Urbanke, C.,Huber, R.,Grazulis, S.,Siksnys, V.
The Crystal Structure of the Rare-Cutting Restriction Enzyme Sdai Reveals Unexpected Domain Architecture
Structure, 14:1389-, 2006

PubMed Abstract: Rare-cutting restriction enzymes are important tools in genome analysis. We report here the crystal structure of SdaI restriction endonuclease, which is specific for the 8 bp sequence CCTGCA/GG ("/" designates the cleavage site). Unlike orthodox Type IIP enzymes, which are single domain proteins, the SdaI monomer is composed of two structural domains. The N domain contains a classical winged helix-turn-helix (wHTH) DNA binding motif, while the C domain shows a typical restriction endonuclease fold. The active site of SdaI is located within the C domain and represents a variant of the canonical PD-(D/E)XK motif. SdaI determinants of sequence specificity are clustered on the recognition helix of the wHTH motif at the N domain. The modular architecture of SdaI, wherein one domain mediates DNA binding while the other domain is predicted to catalyze hydrolysis, distinguishes SdaI from previously characterized restriction enzymes interacting with symmetric recognition sequences.

PubMed: 16962970
DOI: 10.1016/J.STR.2006.07.002

Experimental method

X-RAY DIFFRACTION (2 Å)