Biomaterial Database

Evidence of homology between the pectate lyase-encoding pelB and pelC genes in Erwinia chrysanthemi. 1986

C Schoedel, and A Collmer

The genes for two of several pectate lyase isozymes produced by the phytopathogenic enterobacterium Erwinia chrysanthemi 1237 were subcloned and compared by DNA-DNA hybridization, and the encoded proteins were analyzed. The borders of the genes were located on a restriction map by incremental exonuclease III deletions. DNA-DNA hybridization studies revealed a low percentage of mismatch (7 to 17%) between pelB and pelC. No homology was detected between pelC and other regions of the E. chrysanthemi 1237 chromosome, in which three other isozyme genes apparently reside. The pectate lyase isozymes were readily purified by chromatofocusing or granulated-gel bed isoelectric focusing from the periplasmic shock fluids of Escherichia coli subclones. The molecular weights of PLb and PLc were 30,000 and 33,000 as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Their isoelectric points were 7.6 and 8.1, respectively, as determined by equilibrium isoelectric focusing in ultrathin polyacrylamide gels. The Km values for PLb and PLc were 0.20 and 0.32 mg/ml, respectively, with polygalacturonate as a substrate. Thin-layer chromatography of reaction products and viscometric assays revealed little difference between the two isozymes. All our data indicate that the genes are duplicates and that the proteins are isofunctional.

UI	MeSH Term	Description	Entries
D007526	Isoelectric Point	The pH in solutions of proteins and related compounds at which the dipolar ions are at a maximum.	Isoelectric Points,Point, Isoelectric,Points, Isoelectric
D007527	Isoenzymes	Structurally related forms of an enzyme. Each isoenzyme has the same mechanism and classification, but differs in its chemical, physical, or immunological characteristics.	Alloenzyme,Allozyme,Isoenzyme,Isozyme,Isozymes,Alloenzymes,Allozymes
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008970	Molecular Weight	The sum of the weight of all the atoms in a molecule.	Molecular Weights,Weight, Molecular,Weights, Molecular
D009693	Nucleic Acid Hybridization	Widely used technique which exploits the ability of complementary sequences in single-stranded DNAs or RNAs to pair with each other to form a double helix. Hybridization can take place between two complimentary DNA sequences, between a single-stranded DNA and a complementary RNA, or between two RNA sequences. The technique is used to detect and isolate specific sequences, measure homology, or define other characteristics of one or both strands. (Kendrew, Encyclopedia of Molecular Biology, 1994, p503)	Genomic Hybridization,Acid Hybridization, Nucleic,Acid Hybridizations, Nucleic,Genomic Hybridizations,Hybridization, Genomic,Hybridization, Nucleic Acid,Hybridizations, Genomic,Hybridizations, Nucleic Acid,Nucleic Acid Hybridizations
D010368	Pectins	High molecular weight polysaccharides present in the cell walls of all plants. Pectins cement cell walls together. They are used as emulsifiers and stabilizers in the food industry. They have been tried for a variety of therapeutic uses including as antidiarrheals, where they are now generally considered ineffective, and in the treatment of hypercholesterolemia.	Calcium Pectinate,Methoxy Pectin,Methoxylpectin,Methoxypectin,Pectin,Pectinic Acid,Zinc Pectinate,Pectin, Methoxy,Pectinate, Calcium,Pectinate, Zinc
D011133	Polysaccharide-Lyases	A group of carbon-oxygen lyases. These enzymes catalyze the breakage of a carbon-oxygen bond in polysaccharides leading to an unsaturated product and the elimination of an alcohol. EC 4.2.2.	Polysaccharide Lyase,Polysaccharide-Lyase,Lyase, Polysaccharide,Polysaccharide Lyases
D003001	Cloning, Molecular	The insertion of recombinant DNA molecules from prokaryotic and/or eukaryotic sources into a replicating vehicle, such as a plasmid or virus vector, and the introduction of the resultant hybrid molecules into recipient cells without altering the viability of those cells.	Molecular Cloning
D004262	DNA Restriction Enzymes	Enzymes that are part of the restriction-modification systems. They catalyze the endonucleolytic cleavage of DNA sequences which lack the species-specific methylation pattern in the host cell's DNA. Cleavage yields random or specific double-stranded fragments with terminal 5'-phosphates. The function of restriction enzymes is to destroy any foreign DNA that invades the host cell. Most have been studied in bacterial systems, but a few have been found in eukaryotic organisms. They are also used as tools for the systematic dissection and mapping of chromosomes, in the determination of base sequences of DNAs, and have made it possible to splice and recombine genes from one organism into the genome of another. EC 3.21.1.	Restriction Endonucleases,DNA Restriction Enzyme,Restriction Endonuclease,Endonuclease, Restriction,Endonucleases, Restriction,Enzymes, DNA Restriction,Restriction Enzyme, DNA,Restriction Enzymes, DNA
D004269	DNA, Bacterial	Deoxyribonucleic acid that makes up the genetic material of bacteria.	Bacterial DNA