TY - JOUR
T1 - Retroviral integrases that are improved for processing but impaired for joining
AU - Konsavage, Wesley M.
AU - Sudol, Malgorzata
AU - Lee, Noelle E.
AU - Katzman, Michael
N1 - Funding Information:
We thank Drs. Ira Ropson and John Flanagan for helpful discussions about protein structure and DNA binding. This work was supported by a research grant from the W.W. Smith Charitable Trust. Some early experiments were supported by a research grant from the G. Harold and Leila Y. Mathers Charitable Foundation. During part of this project, M.K. was an MD Research Facilitation Award Scholar of the Penn State College of Medicine and was funded, in part, under a grant with the Pennsylvania Department of Health using Tobacco Settlement Funds; the Department specifically disclaims responsibility for any analyses, interpretations, or conclusions.
PY - 2007/5
Y1 - 2007/5
N2 - Retroviral integrase specifically trims (or processes) the ends of retroviral DNA, then inserts (or joins) these ends into cellular DNA nonspecifically. We previously showed that Rous sarcoma virus integrase with a serine-to-aspartate substitution at amino acid 124 was markedly improved for processing but dramatically impaired for joining, making it the first mutant to separate the activities of integrase in this way. We now show that placing glutamic acid at this residue has the same effect, whereas asparagine or glutamine, which resemble aspartate and glutamate but without the negatively charged acid group, improved processing and impaired joining to a lesser extent. Placing aspartic acid at either of the adjacent residues 123 or 125 also had an intermediate effect. Thus, the charge, structure, and position of the substitution all contribute to the properties of the S124D protein. Infectivity of virions containing these mutations paralleled the in vitro findings, with substitutions having the greatest effect on joining completely blocking replication. Additional studies indicated the replication-defective viruses were blocked at integration and that the S124D protein is impaired at binding nonviral DNA. These functional, biochemical, and genetic data implicate this particular integrase residue as a key part of the binding site for cellular DNA.
AB - Retroviral integrase specifically trims (or processes) the ends of retroviral DNA, then inserts (or joins) these ends into cellular DNA nonspecifically. We previously showed that Rous sarcoma virus integrase with a serine-to-aspartate substitution at amino acid 124 was markedly improved for processing but dramatically impaired for joining, making it the first mutant to separate the activities of integrase in this way. We now show that placing glutamic acid at this residue has the same effect, whereas asparagine or glutamine, which resemble aspartate and glutamate but without the negatively charged acid group, improved processing and impaired joining to a lesser extent. Placing aspartic acid at either of the adjacent residues 123 or 125 also had an intermediate effect. Thus, the charge, structure, and position of the substitution all contribute to the properties of the S124D protein. Infectivity of virions containing these mutations paralleled the in vitro findings, with substitutions having the greatest effect on joining completely blocking replication. Additional studies indicated the replication-defective viruses were blocked at integration and that the S124D protein is impaired at binding nonviral DNA. These functional, biochemical, and genetic data implicate this particular integrase residue as a key part of the binding site for cellular DNA.
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U2 - 10.1016/j.virusres.2007.01.006
DO - 10.1016/j.virusres.2007.01.006
M3 - Article
C2 - 17289204
AN - SCOPUS:34247146377
SN - 0168-1702
VL - 125
SP - 198
EP - 210
JO - Virus Research
JF - Virus Research
IS - 2
ER -
