Structural and Functional Elucidation of AGO Proteins
RNA silencing is a kind of cellular regulating system for mHNA cleavage or translation repression mediated by RNA induced silencing complex (RISC) under sequence-specific direction of small RNAs. As the core component of RISC, AGO(argonaute) protein consists of four domains: N terminus, PAZ, MID and PIWI. PAZ domain recognizes and binds 3' terminal 2 nt overhang of small RNA duplex non-sequence-specifically. 'Conserved pocket' located at the interface between MID and PIWI recognizes and binds the first nucleotide of 5' terminus of small RNA. PIWI domain has a catalytic center for mRNA cleavage. According to the phylogenetic analysis, AGO family is divided into three groups: AGO-like, PIWI-like and GROUP3. Arabidopsis encodes ten AGO proteins (AtAGOs 1-10). Amongst, AtAGOs 1, 4 and 7 have been identified to possess cleavage acitivy, and to be involved in some small RNA pathways. In addition, partially functional redundancy exists between AtAGO1 and AtAGO10, AtAGO1 and AtAGO7, and AtAGO4 and AtAGO6.
NETL
NSTL
万方数据
维普
