3R3P

Homing Endonuclease I-Bth0305I Catalytic Domain

Summary for 3R3P

• Entry DOI: 10.2210/pdb3r3p/pdb
• Descriptor: Mobile intron protein (2 entities in total)
• Functional Keywords: homing endonuclease, hydrolase
• Biological source: Bacillus phage 0305phi8-36
• Total number of polymer chains: 2
• Total formula weight: 24471.93

Authors

Taylor, G.K.,Stoddard, B.L. (deposition date: 2011-03-16, release date: 2011-10-05, Last modification date: 2024-02-21)

Primary citation

Taylor, G.K.,Heiter, D.F.,Pietrokovski, S.,Stoddard, B.L.
Activity, specificity and structure of I-Bth0305I: a representative of a new homing endonuclease family.
Nucleic Acids Res., 39:9705-9719, 2011

PubMed Abstract: Novel family of putative homing endonuclease genes was recently discovered during analyses of metagenomic and genomic sequence data. One such protein is encoded within a group I intron that resides in the recA gene of the Bacillus thuringiensis 03058-36 bacteriophage. Named I-Bth0305I, the endonuclease cleaves a DNA target in the uninterrupted recA gene at a position immediately adjacent to the intron insertion site. The enzyme displays a multidomain, homodimeric architecture and footprints a DNA region of ~60 bp. Its highest specificity corresponds to a 14-bp pseudopalindromic sequence that is directly centered across the DNA cleavage site. Unlike many homing endonucleases, the specificity profile of the enzyme is evenly distributed across much of its target site, such that few single base pair substitutions cause a significant decrease in cleavage activity. A crystal structure of its C-terminal domain confirms a nuclease fold that is homologous to very short patch repair (Vsr) endonucleases. The domain architecture and DNA recognition profile displayed by I-Bth0305I, which is the prototype of a homing lineage that we term the 'EDxHD' family, are distinct from previously characterized homing endonucleases.

PubMed: 21890897
DOI: 10.1093/nar/gkr669

Experimental method

X-RAY DIFFRACTION (2.2 Å)