Clustered Regularly Interspaced Short Palindromic Repeats (CRISPRs) and associated cas genes are essential components of diverse adaptive immune systems that defend bacteria and archaea from infection by foreign genetic elements. But if crRNA-guided immune surveillance is rapid and efficient, then how do phages escape detection and elimination? To date, nearly fifty families of unique Anti-CRISPR proteins (Acrs) have been experimentally demonstrated to suppress type I, II, III or V CRISPR immunity. Aca2 is an anti-CRISPR-associated protein found with various anti-CRISPRs. In the prophage ZF40 of Pectobacterium carotovorum str. ZM1 the aca2 gene is associated with acrIF8 in an acrIF8–aca2 operon. Aca2 is a dimer that represses the expression of the acrIF8–aca2 operon, and that its autoregulation is mediated through binding to inverted repeats in the promoter region. Here you can see a crystal structure of Pectobacterium phage ZF40 apo-aca2 complexed with 26bp DNA synthetic substrate (PDB code: 7VJQ)
#molecularart ... #immolecular .. #CRISPR ... #antiCRISPR ... #phage ... #defense ... #aca2 ... #DNAbinding ... #xray
Rendered with #proteinimaging and finished with #corelphotopaint
#molecularart ... #immolecular .. #CRISPR ... #antiCRISPR ... #phage ... #defense ... #aca2 ... #DNAbinding ... #xray
Rendered with #proteinimaging and finished with #corelphotopaint
