| Literature DB >> 10200256 |
T Kusakabe1, A V Hine, S G Hyberts, C C Richardson.
Abstract
Bacteriophage T7 DNA primase recognizes 5'-GTC-3' in single-stranded DNA. The primase contains a single Cys4 zinc-binding motif that is essential for recognition. Biochemical and mutagenic analyses suggest that the Cys4 motif contacts cytosine of 5'-GTC-3' and may also contribute to thymine recognition. Residues His33 and Asp31 are critical for these interactions. Biochemical analysis also reveals that T7 primase selectively binds CTP in the absence of DNA. We propose that bound CTP selects the remaining base G, of 5'-GTC-3', by base pairing. Our deduced mechanism for recognition of ssDNA by Cys4 motifs bears little resemblance to the recognition of trinucleotides of double-stranded DNA by Cys2His2 zinc fingers.Entities:
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Year: 1999 PMID： 10200256 PMCID： PMC16326 DOI： 10.1073/pnas.96.8.4295
Source DB: PubMed Journal: Proc Natl Acad Sci U S A ISSN： 0027-8424 Impact factor: 11.205