Purification of phi X174 gene C protein

The product of gene C of bacteriophage phi X174 is required for the replication of phiX174 single-stranded DNA in Escherichia coli cells infected with phi X174. The protein has been purified to homogeneity using an in vitro complementation system. The protein exhibits a molecular weight of 5800 under denaturing conditions. The NH2-terminal amino acid sequence of the protein is (NH2)-Met-Arg-Lys, which is consistent with the sequence predicted from the nucleotide sequence of gene C. The protein has an affinity for single-stranded DNA but less for double-stranded DNA.