Functional organization of the murine leukemia virus reverse transcriptase: characterization of a bacterially expressed AKR DNA polymerase deficient in RNase H activity.
The functional organization of the murine leukemia virus reverse transcriptase was investigated by expressing a molecular clone containing AKR MuLV reverse transcriptase-coding sequences in Escherichia coli. A purified preparation of the expressed enzyme (pRT250 reverse transcriptase) consisted primarily of a 69-kilodalton protein that has normal levels of murine leukemia virus polymerase activity but 10-fold-reduced levels of RNase H compared with the viral enzyme. The deficit in RNase H activity was correlated with the absence of 60 to 65 amino acids normally present at the carboxyl end of murine leukemia virus reverse transcriptase. The results provide additional experimental evidence for the localization of polymerase and RNase H domains to the N- and C-terminal regions of reverse transcriptase, respectively.
Levin
J G
JG
Laboratory of Molecular Genetics, National Institute of Child Health and Human Development, Bethesda, Maryland 20892.
Crouch
R J
RJ
Post
K
K
Hu
S C
SC
McKelvin
D
D
Zweig
M
M
Court
D L
DL
Gerwin
B I
BI
D000406:AKR murine leukemia virus / Q000201:enzymology* / Q000235:genetics; D000595:Amino Acid Sequence; D001482:Base Composition; D001665:Binding Sites; D003001:Cloning, Molecular; D004722:Endoribonucleases / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics; D009052:Leukemia Virus, Murine / Q000201:enzymology*; D008969:Molecular Sequence Data; D012194:RNA-Directed DNA Polymerase / Q000235:genetics* / Q000502:physiology; D016914:Ribonuclease H; D014764:Viral Proteins / Q000235:genetics / Q000502:physiology
D014764:Viral Proteins; D012194:RNA-Directed DNA Polymerase; D004722:Endoribonucleases; D016914:Ribonuclease H