title: Chitinase determinants of Vibrio vulnificus: gene cloning and applications of a chitinase probe.
abstract: To initiate study of the genetic control of chitinolytic activity in vibrios, the chitobiase gene was isolated by cloning chromosomal DNA prepared from Vibrio vulnificus. Chimeric plasmids were constructed from Sau3A I partial digests of chromosomal DNA by ligating 5 to 15-kilobase fragments into the BamHI site, i.e., in the Tcr gene, of pBR322 (Amr Tcr). The resulting plasmids were transformed into Escherichia coli DH1. Chitobiase activity of the insert-bearing clones was detected by using a chromogenic substrate, p-nitrophenyl-N-acetyl-beta, D-glucosaminide, and confirmed by the appearance of a fluorescent end product from the hydrolysis of 4-methylumbelliferyl-beta,D-N-N'-diacetylchitobiose. Endochitinase activity was demonstrated by liberation of water-soluble products produced by the degradation of [3H]chitin. Transformation of E. coli Y10R (lacY) with plasmids from chitinase-positive clones restored the lactose-positive phenotype, suggesting the presence of a permease associated with chitinase activity. Physical mapping of plasmids containing the chitinase determinants indicate that transcription of these genes in E. coli may be initiated at a V. vulnificus promoter.
mesh_terms: D002686:Chitin / Q000378:metabolism; D002688:Chitinases / Q000235:genetics* / Q000378:metabolism; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000235:genetics; D005798:Genes, Bacterial; D010957:Plasmids; D012623:Seawater; D014169:Transformation, Bacterial; D014733:Vibrio / Q000201:enzymology / Q000235:genetics*; D014871:Water Microbiology
chemical_list: D002686:Chitin; D002688:Chitinases