Functional analysis of human cytomegalovirus polymerase accessory protein.
The human cytomegalovirus (HCMV) UL44 gene product, polymerase accessory protein, was cloned and expressed in Escherichia coli as a 53,000 MW protein. The activity of HCMV DNA polymerase (Pol) alone and Pol/UL44 complex was evaluated in Pol assays designed specifically to elucidate Pol/UL44 interactions. Addition of UL44 to HCMV Pol with primed, single-stranded DNA resulted in increased incorporation of nucleotides into DNA, which was correlated with enhanced enzyme processivity. Several deletion mutants which span the UL44 sequence were constructed and examined for the ability to stimulate Pol activity and to bind double-stranded DNA. The functional domains of UL44 protein were determined to reside within the N-terminal 309 amino acids of the wild type sequence, since deletions within this region resulted in loss of DNA binding and the ability to stimulate Pol. Deletion of C-terminal amino acids 310-433 had no effect on the ability of UL44 protein to increase the processivity of HCMV DNA Pol.
Upjohn Laboratories, Upjohn Company, Kalamazoo, MI 49001.
K L
KL
Weiland
N L
NL
Oien
F
F
Homa
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MW
Wathen
D018528:ATP-Binding Cassette Transporters; D002352:Carrier Proteins / Q000235:genetics; D003587:Cytomegalovirus / Q000201:enzymology* / Q000235:genetics; D004279:DNA, Viral / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D004259:DNA-Directed DNA Polymerase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004789:Enzyme Activation; D004926:Escherichia coli; D029968:Escherichia coli Proteins; D015967:Gene Expression Regulation, Viral; D006801:Humans; D058619:Maltose-Binding Proteins; D008969:Molecular Sequence Data; D009004:Monosaccharide Transport Proteins; D011485:Protein Binding; D011993:Recombinant Fusion Proteins; D017384:Sequence Deletion; D013268:Stimulation, Chemical; D014764:Viral Proteins / Q000235:genetics / Q000378:metabolism*
D018528:ATP-Binding Cassette Transporters; D002352:Carrier Proteins; D004279:DNA, Viral; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; C072217:ICP36 protein, Cytomegalovirus; D058619:Maltose-Binding Proteins; D009004:Monosaccharide Transport Proteins; D011993:Recombinant Fusion Proteins; D014764:Viral Proteins; C461599:maltose transport system, E coli; D004259:DNA-Directed DNA Polymerase