Characterization of two chitinase genes and one chitosanase gene encoded by Chlorella virus PBCV-1.
Chlorella virus PBCV-1 encodes two putative chitinase genes, a181/182r and a260r, and one chitosanase gene, a292l. The three genes were cloned and expressed in Escherichia coli. The recombinant A181/182R protein has endochitinase activity, recombinant A260R has both endochitinase and exochitinase activities, and recombinant A292L has chitosanase activity. Transcription of a181/182r, a260r, and a292l genes begins at 30, 60, and 60 min p.i., respectively; transcription of all three genes continues until the cells lyse. A181/182R, A260R, and A292L proteins are first detected by Western blots at 60, 90, and 120 min p.i., respectively. Therefore, a181/182r is an early gene and a260r and a292l are late genes. All three genes are widespread in chlorella viruses. Phylogenetic analyses indicate that the ancestral condition of the a181/182r gene arose from the most recent common ancestor of a gene found in tobacco, whereas the genealogical position of the a260r gene could not be unambiguously resolved.
Sun
L
L
Department of Plant Pathology, University of Nebraska, Lincoln, Nebraska 68583-0722, USA.
Adams
B
B
Gurnon
J R
JR
Ye
Y
Y
Van Etten
J L
JL
D000595:Amino Acid Sequence; D002688:Chitinases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D002708:Chlorella / Q000821:virology; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000235:genetics; D005814:Genes, Viral / Q000235:genetics*; D006026:Glycoside Hydrolases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009693:Nucleic Acid Hybridization; D016366:Open Reading Frames / Q000235:genetics; D017862:Phycodnaviridae / Q000201:enzymology / Q000235:genetics*; D010802:Phylogeny; D014176:Protein Biosynthesis; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D013379:Substrate Specificity; D014158:Transcription, Genetic / Q000235:genetics; D014764:Viral Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; D014764:Viral Proteins; D006026:Glycoside Hydrolases; C019868:chitosanase; D002688:Chitinases