title: Organization and characterization of three genes involved in D-xylose catabolism in Lactobacillus pentosus.
abstract: A cluster of three genes involved in D-xylose catabolism (viz. xylose genes) in Lactobacillus pentosus has been cloned in Escherichia coli and characterized by nucleotide sequence analysis. The deduced gene products show considerable sequence similarity to a repressor protein involved in the regulation of expression of xylose genes in Bacillus subtilis (58%), to E. coli and B. subtilis D-xylose isomerase (68% and 77%, respectively), and to E. coli D-xylulose kinase (58%). The cloned genes represent functional xylose genes since they are able to complement the inability of a L. casei strain to ferment D-xylose. NMR analysis confirmed that 13C-xylose was converted into 13C-acetate in L. casei cells transformed with L. pentosus xylose genes but not in untransformed L. casei cells. Comparison with the aligned amino acid sequences of D-xylose isomerases of different bacteria suggests that L. pentosus D-xylose isomerase belongs to the same similarity group as B. subtilis and E. coli D-xylose isomerase and not to a second similarity group comprising D-xylose isomerases of Streptomyces violaceoniger, Ampullariella sp. and Actinoplanes. The organization of the L. pentosus xylose genes, 5'-xylR (1167 bp, repressor) - xylA (1350 bp, D-xylose isomerase) - xylB (1506 bp, D-xylulose kinase) - 3' is similar to that in B. subtilis. In contrast to B. subtilis xylR, L. pentosus xylR is transcribed in the same direction as xylA and xylB.
authors.affiliation: TNO Medical Biological Laboratory, Rijswijk, The Netherlands.
authors.forename: B C
authors.initials: BC
authors.lastname: Lokman
authors.forename: P
authors.initials: P
authors.lastname: van Santen
authors.forename: J C
authors.initials: JC
authors.lastname: Verdoes
authors.forename: J
authors.initials: J
authors.lastname: Krüse
authors.forename: R J
authors.initials: RJ
authors.lastname: Leer
authors.forename: M
authors.initials: M
authors.lastname: Posno
authors.forename: P H
authors.initials: PH
authors.lastname: Pouwels
mesh_terms: D019747:Aldose-Ketose Isomerases; D000595:Amino Acid Sequence; D001412:Bacillus subtilis / Q000201:enzymology / Q000235:genetics; D001483:Base Sequence; D002238:Carbohydrate Epimerases / Q000235:genetics; D003001:Cloning, Molecular; D004269:DNA, Bacterial / Q000235:genetics; D005798:Genes, Bacterial; D007778:Lactobacillus / Q000235:genetics*; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D005810:Multigene Family; D016366:Open Reading Frames; D010770:Phosphotransferases / Q000235:genetics; D017853:Phosphotransferases (Alcohol Group Acceptor); D010957:Plasmids; D012097:Repressor Proteins / Q000235:genetics; D015183:Restriction Mapping; D016415:Sequence Alignment; D012689:Sequence Homology, Nucleic Acid; D013302:Streptomyces / Q000201:enzymology; D014994:Xylose / Q000378:metabolism*
chemical_list: D004269:DNA, Bacterial; D012097:Repressor Proteins; D014994:Xylose; D010770:Phosphotransferases; D017853:Phosphotransferases (Alcohol Group Acceptor); C032700:xylulokinase; D002238:Carbohydrate Epimerases; D019747:Aldose-Ketose Isomerases; C023298:xylose isomerase