GONUTS has been updated to MW1.31 Most things seem to be working but be sure to report problems.

Have any questions? Please email us at ecoliwiki@gmail.com

PMID:12192057

From GONUTS
Jump to: navigation, search
Citation

Lin, BY, Makhov, AM, Griffith, JD, Broker, TR and Chow, LT (2002) Chaperone proteins abrogate inhibition of the human papillomavirus (HPV) E1 replicative helicase by the HPV E2 protein. Mol. Cell. Biol. 22:6592-604

Abstract

Human papillomavirus (HPV) DNA replication requires the viral origin recognition protein E2 and the presumptive viral replicative helicase E1. We now report for the first time efficient DNA unwinding by a purified HPV E1 protein. Unwinding depends on a supercoiled DNA substrate, topoisomerase I, single-stranded-DNA-binding protein, and ATP, but not an origin. Electron microscopy revealed completely unwound molecules. Intermediates contained two single-stranded loops emanating from a single protein complex, suggesting a bidirectional E1 helicase which translocated the flanking DNA in an inward direction. We showed that E2 protein partially inhibited DNA unwinding and that Hsp70 or Hsp40, which we reported previously to stimulate HPV-11 E1 binding to the origin and promote dihexameric E1 formation, apparently displaced E2 and abolished inhibition. Neither E2 nor chaperone proteins were detected in unwinding complexes. These results suggest that chaperones play important roles in the assembly and activation of a replicative helicase in higher eukaryotes. An E1 mutation in the ATP binding site caused deficient binding and unwinding of origin DNA, indicating the importance of ATP binding in efficient helicase assembly on the origin.

Links

PubMed PMC135630

Keywords

Adenosine Triphosphatases/metabolism; Adenosine Triphosphate/metabolism; Animals; Binding Sites; Cell Line; Cell-Free System; Chloroquine/pharmacology; DNA/ultrastructure; DNA Topoisomerases, Type I/metabolism; DNA, Superhelical; DNA-Binding Proteins/chemistry; DNA-Binding Proteins/metabolism; Electrophoresis, Agar Gel; Humans; Immunohistochemistry; Insecta; Microscopy, Electron; Models, Biological; Mutation; Nucleic Acid Conformation; Papillomaviridae/metabolism; Plasmids/metabolism; Protein Binding; Viral Proteins/chemistry; Viral Proteins/metabolism

Significance

Annotations

Gene product Qualifier GO Term Evidence Code with/from Aspect Extension Notes Status

HPV11:VE1

involved_in

GO:0039686: bidirectional double-stranded viral DNA replication

ECO:0000314: direct assay evidence used in manual assertion

P

Seeded From UniProt

complete

HPV11:VE1

enables

GO:0003678: DNA helicase activity

ECO:0000314: direct assay evidence used in manual assertion

F

Seeded From UniProt

complete

HPV11:VE1

involved_in

GO:0034214: protein hexamerization

ECO:0000314: direct assay evidence used in manual assertion

P

Seeded From UniProt

complete

HPV11:VE1

involved_in

GO:0032508: DNA duplex unwinding

ECO:0000314: direct assay evidence used in manual assertion

P

Seeded From UniProt

complete

Notes

See also

References

See Help:References for how to manage references in GONUTS.