title: Identification and preliminary characterization of a chitinase gene in the Autographa californica nuclear polyhedrosis virus genome.
abstract: A functional chitinase gene (chiA) has been identified in the genome of the Autographa californica nuclear polyhedrosis virus (AcMNPV). It is expressed in the late phase of virus replication in insect cells. High levels of both endo- and exochitinase activity were detected by 12 hr p.i. and remained stable throughout infection. An AcMNPV chiA protein-specific antibody was prepared using recombinant material prepared in bacteria. This was used to demonstrate that a product of approximately 58 kDa was synthesised in virus-infected cells. Immunofluorescence analysis of virus-infected cells showed that most chitinase was located in the cytoplasm. Primer extension analysis of mRNA from AcMNPV-infected cells confirmed that transcription initiated from a baculovirus late start site (TAAG), 14 nucleotides upstream from the putative translation initiation codon. The predicted protein sequence of the AcMNPV chiA shares extensive sequence similarity with chitinases from bacteria and, in particular, the Serratia marcescens chitinase A (60.5% identical residues). Phylogenetic analyses indicate that AcMNPV, or an ancestral baculovirus, acquired the chitinase gene from a bacterium via horizontal gene transfer.
authors.affiliation: NERC Institute of Virology and Environmental Microbiology, Oxford, United Kingdom.
authors.forename: R E
authors.initials: RE
authors.lastname: Hawtin
authors.forename: K
authors.initials: K
authors.lastname: Arnold
authors.forename: M D
authors.initials: MD
authors.lastname: Ayres
authors.forename: P M
authors.initials: PM
authors.lastname: Zanotto
authors.forename: S C
authors.initials: SC
authors.lastname: Howard
authors.forename: G W
authors.initials: GW
authors.lastname: Gooday
authors.forename: L H
authors.initials: LH
authors.lastname: Chappell
authors.forename: P A
authors.initials: PA
authors.lastname: Kitts
authors.forename: L A
authors.initials: LA
authors.lastname: King
authors.forename: R D
authors.initials: RD
authors.lastname: Possee
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000914:Antibodies, Viral; D001482:Base Composition; D001483:Base Sequence; D002460:Cell Line; D002688:Chitinases / Q000737:chemistry / Q000235:genetics* / Q000276:immunology / Q000378:metabolism; D003593:Cytoplasm / Q000201:enzymology; D019143:Evolution, Molecular; D015971:Gene Expression Regulation, Enzymologic; D005814:Genes, Viral / Q000235:genetics*; D008969:Molecular Sequence Data; D017924:Nucleopolyhedroviruses / Q000201:enzymology / Q000235:genetics* / Q000276:immunology / Q000502:physiology; D010802:Phylogeny; D012333:RNA, Messenger / Q000096:biosynthesis; D012367:RNA, Viral / Q000096:biosynthesis; D011994:Recombinant Proteins / Q000276:immunology; D017386:Sequence Homology, Amino Acid; D018411:Spodoptera; D014158:Transcription, Genetic / Q000235:genetics; D015678:Viral Structural Proteins / Q000235:genetics*; D014779:Virus Replication
chemical_list: D000914:Antibodies, Viral; D012333:RNA, Messenger; D012367:RNA, Viral; D011994:Recombinant Proteins; D015678:Viral Structural Proteins; D002688:Chitinases; C094590:chitinase ChiA