PMID- 1370463
OWN - NLM
STAT- MEDLINE
DCOM- 19920214
LR  - 20210210
IS  - 0021-9258 (Print)
IS  - 0021-9258 (Linking)
VI  - 267
IP  - 2
DP  - 1992 Jan 15
TI  - The effects of cysteine mutations on the reverse transcriptases of human 
      immunodeficiency virus types 1 and 2.
PG  - 1293-7
AB  - Chemical modification of HIV-1 and HIV-2 (human immunodeficiency virus, types 1 
      and 2) reverse transcriptases (RT) with three thiol reactive compounds 
      selectively inhibits the RNase H function of the enzyme. HIV-1 RT has 2 cysteines 
      (at positions 38 and 280); HIV-2 RT has 3 (38, 280, 445). Both of the cysteines 
      in HIV-1 RT are in the polymerase domain. To investigate the role of the 
      cysteines in the structure and function of the HIV RTs, we have converted each 
      cysteine to serine and made combinations of the mutations. Since HIV-1 RT has 
      alanine at position 445, we have also substituted alanine for serine at this 
      position in HIV-2 RT. Neither of the single mutations in HIV-1 RT nor the double 
      mutation mimics the effects of the chemical modification. The serine 280 mutation 
      has little effect on either polymerase or RNase H; the serine 38 mutation affects 
      both activities, as does the 38/280 double mutant. The 38 and 280 serine 
      mutations in HIV-2 RT resemble the equivalent mutations in HIV-1 RT. Substitution 
      of serine or alanine at position 445 (which lies in the RNase H domain) 
      diminishes, but does not abolish, the RNase H activity of HIV-2 without affecting 
      polymerase activity. The RNase H activity of a mutant HIV-1 RT with serine at 
      position 280 is completely resistant to inactivation by the three thiol reactive 
      compounds we tested, which demonstrates that cysteine 280 is the critical 
      residue. We suggest that the reason the mutation (cysteine 280 to serine) does 
      not mimic the chemical modification is because the chemical modification produces 
      a greater change in the structure of the protein. We also suggest that position 
      280 lies at or near the important points of contact between the RNase H and 
      polymerase domains, so that chemical modification of this position, which lies 
      within the polymerase domain, distorts the RNase H domain.
FAU - Hizi, A
AU  - Hizi A
AD  - Department of Cell Biology and Histology, Sackler School of Medicine, Tel Aviv 
      University, Israel.
FAU - Shaharabany, M
AU  - Shaharabany M
FAU - Tal, R
AU  - Tal R
FAU - Hughes, S H
AU  - Hughes SH
LA  - eng
GR  - N01-CO-74101/CO/NCI NIH HHS/United States
GR  - R01-AI27035/AI/NIAID NIH HHS/United States
PT  - Journal Article
PT  - Research Support, U.S. Gov't, P.H.S.
PL  - United States
TA  - J Biol Chem
JT  - The Journal of biological chemistry
JID - 2985121R
RN  - 0 (Reverse Transcriptase Inhibitors)
RN  - 0 (Sulfhydryl Compounds)
RN  - EC 2.7.7.- (reverse transcriptase, Human immunodeficiency virus 2)
RN  - EC 2.7.7.49 (HIV Reverse Transcriptase)
RN  - EC 2.7.7.49 (RNA-Directed DNA Polymerase)
RN  - EC 2.7.7.7 (DNA-Directed DNA Polymerase)
RN  - EC 3.1.26.4 (Ribonuclease H)
RN  - K848JZ4886 (Cysteine)
SB  - IM
MH  - Cysteine/*genetics
MH  - DNA-Directed DNA Polymerase/metabolism
MH  - Electrophoresis, Polyacrylamide Gel
MH  - Escherichia coli/enzymology
MH  - Gene Expression
MH  - HIV Reverse Transcriptase
MH  - HIV-1/*enzymology
MH  - HIV-2/*enzymology
MH  - *Mutation
MH  - RNA-Directed DNA Polymerase/*genetics/metabolism
MH  - Reverse Transcriptase Inhibitors
MH  - Ribonuclease H/antagonists & inhibitors/metabolism
MH  - Sulfhydryl Compounds/pharmacology
EDAT- 1992/01/15 00:00
MHDA- 1992/01/15 00:01
CRDT- 1992/01/15 00:00
PHST- 1992/01/15 00:00 [pubmed]
PHST- 1992/01/15 00:01 [medline]
PHST- 1992/01/15 00:00 [entrez]
AID - S0021-9258(18)48428-1 [pii]
PST - ppublish
SO  - J Biol Chem. 1992 Jan 15;267(2):1293-7.