The dhfr oribeta-binding protein RIP60 contains 15 zinc fingers: DNA binding and looping by the central three fingers and an associated proline-rich region.

ABSTRACT: Initiation of DNA replication occurs with high frequency within oribeta, a short region 3' to the Chinese hamster dhfr gene. Homodimers of RIP60 (replication initiation-region protein 60 kDA) purified from nuclear extract bind two ATT-rich sites in oribeta and foster the formation of a twisted 720 bp DNA loop in vitro. Using a one hybrid screen in yeast, we have cloned the cDNA for human RIP60. RIP60 contains 15 C(2)H(2)zinc finger (ZF) DNA binding motifs organized in three clusters, termed hand Z1 (ZFs 1-5), hand Z2 (ZFs 6-8) and hand Z3 (ZFs 9-15). A proline-rich region is located between hands Z2 and Z3. Gel mobility shift and DNase I footprinting experiments show hands Z1 and Z2 independently bind the oribeta RIP60 sites specifically, but with different affinities. Hand Z3 binds DNA, b

SUBMITTER: Houchens CR 

PROVIDER: S-EPMC102514 | biostudies-literature | 2000 Jan

REPOSITORIES: biostudies-literature