Structure of HK97 small terminase:DNA complex unveils a novel DNA binding mechanism by a circular protein.

ABSTRACT: DNA recognition is critical for assembly of double-stranded DNA viruses, in particular for the initiation of packaging the viral genome into the capsid. DNA packaging has been extensively studied for three archetypal bacteriophage systems: cos, pac and phi29. We identified the minimal site within the cos region of bacteriophage HK97 specifically recognised by the small terminase and determined a cryoEM structure for the small terminase:DNA complex. This nonameric circular protein utilizes a previously unknown mechanism of DNA binding. While DNA threads through the central tunnel, unexpectedly, DNA-recognition is generated at its exit by a substructure formed by the N- and C-terminal segments of two adjacent protomers of the terminase which are unstructured in the absen

SUBMITTER: Chechik M 

PROVIDER: S-EPMC10370121 | biostudies-literature | 2023 Jul

REPOSITORIES: biostudies-literature