TY - JOUR
T1 - Cytomegalovirus basic phosphoprotein (pUL32) binds to capsids in vitro through its amino one-third
AU - Baxter, M. K.
AU - Gibson, W.
PY - 2001
Y1 - 2001
N2 - The cytomegalovirus (CMV) basic phosphoprotein (BPP) is a component of the tegument. It remains with the nucleocapsid fraction under conditions that remove most other tegument proteins from the virion, suggesting a direct and perhaps tight interaction with the capsid. AS a step toward localizing this protein within the molecular structure of the virion and understanding its function during infection, we have investigated the BPP-capsid interaction. In this report we present evidence that the BPP interacts selectively, through its amino one-third, with CMV capsids. Radiolabeled simian CMV (SCMV) BPP, synthesized in vitro, bound to SCMV B-capsids, and C-capsids to a lesser extent, following incubation with either isolated capsids or lysates of infected cells. Human CMV (HCMV) BPP (pUL32) also bound to SCMV capsids, and SCMV BPP likewise bound to HCMV capsids, indicating that the sequence(s) involved is conserved between the two proteins. Analysis of SCMV BPP truncation mutants localized the capsid-binding region to the amino one-third of the molecule - the portion of BPP showing the greatest sequence conservation between the SCMV and HCMV homologs. This general approach may have utility in studying the interactions of other proteins with conformation-dependent binding sites.
AB - The cytomegalovirus (CMV) basic phosphoprotein (BPP) is a component of the tegument. It remains with the nucleocapsid fraction under conditions that remove most other tegument proteins from the virion, suggesting a direct and perhaps tight interaction with the capsid. AS a step toward localizing this protein within the molecular structure of the virion and understanding its function during infection, we have investigated the BPP-capsid interaction. In this report we present evidence that the BPP interacts selectively, through its amino one-third, with CMV capsids. Radiolabeled simian CMV (SCMV) BPP, synthesized in vitro, bound to SCMV B-capsids, and C-capsids to a lesser extent, following incubation with either isolated capsids or lysates of infected cells. Human CMV (HCMV) BPP (pUL32) also bound to SCMV capsids, and SCMV BPP likewise bound to HCMV capsids, indicating that the sequence(s) involved is conserved between the two proteins. Analysis of SCMV BPP truncation mutants localized the capsid-binding region to the amino one-third of the molecule - the portion of BPP showing the greatest sequence conservation between the SCMV and HCMV homologs. This general approach may have utility in studying the interactions of other proteins with conformation-dependent binding sites.
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U2 - 10.1128/JVI.75.15.6865-6873.2001
DO - 10.1128/JVI.75.15.6865-6873.2001
M3 - Article
C2 - 11435566
AN - SCOPUS:0034947771
SN - 0022-538X
VL - 75
SP - 6865
EP - 6873
JO - Journal of Virology
JF - Journal of Virology
IS - 15
ER -