Browsing tag: białko C

Regulacja bakteryjnych systemów restrykcyjno-modyfikacyjnych (R-M) typu II

Regulation of bacterial type II restriction-modification (R-M) systems
M. Wesserling

1. Wstęp. 2. Sposoby regulacji ekspresji genów systemów R-M typu II. 2.1. Kontrola ekspresji genów systemu R-M poprzez metylotransferazę. 2.2. Gen endonukleazy restrykcyjnej położony za genem metylotransferazy. 2.3. Regulacja ekspresji genów poprzez antysensowne RNA. 3. Białka kontrolujące C. 4. Struktura miejsc DNA do których wiąże się białko C (operator). 5. Mechanizm regulacji transkrypcji przez białko C. 6. Podsumowanie

Abstract: Type II restriction-modification (R-M) systems encode two separate enzymes: a restriction endonuclease (R) and a DNA methyltransferase (M). The action of the DNA sequence-specific methyltransferase protects the host DNA from cleavage by an associated restriction enzyme. The function of type II restriction-modification system regulation is generally assumed to be prevention of bacterial cell auto-restriction. The R and M genes must be regulated in such a way that the cell’s own DNA is fully protected before restriction endonuclease activity appears. There a variety of control mechanisms that ensure the correct temporal expression of R-M genes. Unfortunately, the regulation mechanisms have not been well explored thus far. The understanding of the expression regulation of R-M genes is important and may influence the direction of research on new therapeutic methods.

1. Introduction. 2. Regulation of type II R-M gene expression systems. 2.1. Control of R-M gene expression by methyltransferase. 2.2. Restriction endonuclease gene located downstream of the methyltransferase gene. 2.3. Regulation of gene expression by antisense RNA. 3. Controller proteins. 4. The structure of C protein binding sites. 5. The mechanism of transcription regulation by C protein. 6. Summary