Protein Family Models

This domain is also known as the target recognition domain (TRD). Restriction-modification (R-M) systems protect a bacterial cell against invasion of foreign DNA by endonucleolytic cleavage of DNA that lacks a site specific modification. The host genome is protected from cleavage by methylation of specific nucleotides in the target sites. In type I systems, both restriction and modification activities are present in one heteromeric enzyme complex composed of one DNA specificity subunit (this family), two modification (M) subunits and two restriction (R) subunits [2]. [1]. 8336674. Biology of DNA restriction.. Bickle TA, Kruger DH;. Microbiol Rev 1993;57:434-450.. [2]. 9837717. The DNA recognition subunit of the type IB. restriction-modification enzyme EcoAI tolerates circular. permutions of its polypeptide chain.. Janscak P, Bickle TA;. J Mol Biol 1998;284:937-948. (from Pfam)

Date:

2024-08-14

type I restriction-modification system specificity (S) subunit (HsdS) dictates DNA sequence specificity; it consists of two variable target recognition domains (TRD1 and 2) and two conserved regions (CR1 and CR2) which separate the TRDs; each TRD binds to different specific sequences in the DNA

Date:

2017-06-14