TY - JOUR
T1 - Chlorella virus PBCV-1 encodes functional glutamine
T2 - Fructose-6- phosphate amidotransferase and UDP-glucose dehydrogenase enzymes
AU - Landstein, Dorit
AU - Graves, Michael V.
AU - Burbank, Dwight E.
AU - Deangelis, Paul
AU - Van Etten, James L.
N1 - Funding Information:
We thank Les Lane, Mike Nelson, and Bryon Adams for helpful discussions and Stewart Shuman for the a103r gene probe. This manuscript has been assigned Journal Series No. 12251, Agricultural Research Division, University of Nebraska. This investigation was supported, in part, by an AOC grant from the University of Nebraska Biotechnology Center (J.V.E.), NSF-EPSCoR cooperative agreement EPS-9255225 (J.V.E.), and Public Health Service Grants GM-32441 (J.V.E.) and GM-56497 (P.D.) from the National Institute of General Medical Sciences.
PY - 1998/10/25
Y1 - 1998/10/25
N2 - DNA sequence analysis of the 330-kb Chlorella virus PBCV-1 genome unexpectedly revealed several open reading frames which encode proteins that are homologous to sugar-manipulating enzymes including glutamine:fructose-6- phosphate amidotransferase (GFAT), UDP-glucose dehydrogenase (UDP-GlcDH), and hyaluronan synthase (HAS). PBCV-1 genes encoding the putative GFAT and UDP- GlcDH enzymes were expressed in Escherichia coli and both recombinant proteins have the predicted enzyme activity in cell free extracts. These same two genes are transcribed early in PBCV-1 infection, and both genes are widespread among the Chlorella viruses. The products of the reactions catalyzed by these two enzymes are precursors in the biosynthesis of hyaluronan polysaccharide. Previous experiments established that, like the GFAT and UDP-GlcDH genes, the HAS gene is transcribed early and encodes a functional enzyme (DeAngelis, P.L., Jing. W., Graves, M.V., Burbank, D.E., and Van Etten, J.L. (1997) Science 278, 1800-1803). Interestingly, the predicted amino-acid sequences of the PBCV-1 GFAT and UDP-GlcDH enzymes are more similar to bacterial GFAT and UDP-GlcDH enzymes than to their eukaryotic counterparts. In contrast, the amino-acid sequence of the PBCV-1 HAS enzyme more closely resembles eukaryotic enzymes.
AB - DNA sequence analysis of the 330-kb Chlorella virus PBCV-1 genome unexpectedly revealed several open reading frames which encode proteins that are homologous to sugar-manipulating enzymes including glutamine:fructose-6- phosphate amidotransferase (GFAT), UDP-glucose dehydrogenase (UDP-GlcDH), and hyaluronan synthase (HAS). PBCV-1 genes encoding the putative GFAT and UDP- GlcDH enzymes were expressed in Escherichia coli and both recombinant proteins have the predicted enzyme activity in cell free extracts. These same two genes are transcribed early in PBCV-1 infection, and both genes are widespread among the Chlorella viruses. The products of the reactions catalyzed by these two enzymes are precursors in the biosynthesis of hyaluronan polysaccharide. Previous experiments established that, like the GFAT and UDP-GlcDH genes, the HAS gene is transcribed early and encodes a functional enzyme (DeAngelis, P.L., Jing. W., Graves, M.V., Burbank, D.E., and Van Etten, J.L. (1997) Science 278, 1800-1803). Interestingly, the predicted amino-acid sequences of the PBCV-1 GFAT and UDP-GlcDH enzymes are more similar to bacterial GFAT and UDP-GlcDH enzymes than to their eukaryotic counterparts. In contrast, the amino-acid sequence of the PBCV-1 HAS enzyme more closely resembles eukaryotic enzymes.
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U2 - 10.1006/viro.1998.9388
DO - 10.1006/viro.1998.9388
M3 - Article
C2 - 9792849
AN - SCOPUS:0032566906
SN - 0042-6822
VL - 250
SP - 388
EP - 396
JO - Virology
JF - Virology
IS - 2
ER -