- PDB ID:
- Source: Lambda phage's enzyme functioning in E.coli host
- Classification Keyword: integrase, tyrosine recombinase
- Size: 356 aa
- Enzyme Structure
- crystal structure of C-terminal catalytic domain is known
- N-terminal 1-64 aa binds to arm-type site.
- C-terminal 65-169 aa binds to low affinity core-type site.
- 170-356 aa is the minimal catalytic domain which include six tyrosine kinase conserved residues: R212, K235, H308, R311, Y342, H308 (nucleophilic tyrosine and catalytic pentad)
- attB:: has two inverted repeated sequence flanking an overlap region. Inverted repeated sequence (core-type) is about 9-13 bps.
- attP is more complicated, with arm-type sites flanking core-type site.
- The overlap region (between attP and attB) is about 6-8 bps and shares sequence with attP. Here is where crossing over occur. Overlap-region:TTTATAC:
- auxiliary factors:
- Mechanism: high affinity binding at arm-region of attP, low affinity binding at core-region. Integration host factor (IHF, from HimA and hip genes) is required for sharp bending in DNA, allowing the integrase bound at arm-type site to also bind at the low affinity core-type sites. Break one strand at the time. Tyrosine phosphate binds to 3'end . 5'OH is free. Integration involve holiday junction
- Invitrogen Gateway (r) system