Biomaterial Database

Mutational analysis of the Lactococcus lactis NIZO B40 exopolysaccharide (EPS) gene cluster: EPS biosynthesis correlates with unphosphorylated EpsB. 2007

M N Nierop Groot, and M Kleerebezem

TI Food and Nutrition, NIZO food research, Health and Safety Department, Ede, The Netherlands.

OBJECTIVE To determine the role of the EpsA, EpsB, and EpsC proteins encoded at the 5'-end of the exopolysaccharide (EPS) gene cluster in regulation of EPS production in Lactococcus lactis. RESULTS Deletion and paralog-replacement mutants of epsABCD were used to determine the function of EpsA, EpsB and EpsC in EPS production and polymer chain length determination in L. lactis. EpsA and EpsB appeared to be essential for EPS biosynthesis in L. lactis, while deletion of the phosphatase (EpsC) only had a minor effect on the EPS production level. Determination of the phosphorylation state of EpsB and analysis of a C-terminally truncated EpsB variant indicate that EPS biosynthesis in L. lactis is driven by a nonphosphorylated form of EpsB. CONCLUSIONS The data presented here show that in L. lactis, EPS production is under control of a phosphoregulatory system and that EPS biosynthesis correlates with an unphosphorylated EpsB. CONCLUSIONS This study provides molecular understanding of polysaccharide production in L. lactis that could eventually enable novel approaches to control EPS production by lactic acid bacteria during industrial fermentation processes.

UI	MeSH Term	Description	Entries
D007218	Industrial Microbiology	The study, utilization, and manipulation of those microorganisms capable of economically producing desirable substances or changes in substances, and the control of undesirable microorganisms.	Microbiology, Industrial
D008969	Molecular Sequence Data	Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.	Sequence Data, Molecular,Molecular Sequencing Data,Data, Molecular Sequence,Data, Molecular Sequencing,Sequencing Data, Molecular
D010766	Phosphorylation	The introduction of a phosphoryl group into a compound through the formation of an ester bond between the compound and a phosphorus moiety.	Phosphorylations
D011135	Polysaccharides, Bacterial	Polysaccharides found in bacteria and in capsules thereof.	Bacterial Polysaccharides
D004252	DNA Mutational Analysis	Biochemical identification of mutational changes in a nucleotide sequence.	Mutational Analysis, DNA,Analysis, DNA Mutational,Analyses, DNA Mutational,DNA Mutational Analyses,Mutational Analyses, DNA
D005810	Multigene Family	A set of genes descended by duplication and variation from some ancestral gene. Such genes may be clustered together on the same chromosome or dispersed on different chromosomes. Examples of multigene families include those that encode the hemoglobins, immunoglobulins, histocompatibility antigens, actins, tubulins, keratins, collagens, heat shock proteins, salivary glue proteins, chorion proteins, cuticle proteins, yolk proteins, and phaseolins, as well as histones, ribosomal RNA, and transfer RNA genes. The latter three are examples of reiterated genes, where hundreds of identical genes are present in a tandem array. (King & Stanfield, A Dictionary of Genetics, 4th ed)	Gene Clusters,Genes, Reiterated,Cluster, Gene,Clusters, Gene,Families, Multigene,Family, Multigene,Gene Cluster,Gene, Reiterated,Multigene Families,Reiterated Gene,Reiterated Genes
D001426	Bacterial Proteins	Proteins found in any species of bacterium.	Bacterial Gene Products,Bacterial Gene Proteins,Gene Products, Bacterial,Bacterial Gene Product,Bacterial Gene Protein,Bacterial Protein,Gene Product, Bacterial,Gene Protein, Bacterial,Gene Proteins, Bacterial,Protein, Bacterial,Proteins, Bacterial
D001483	Base Sequence	The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.	DNA Sequence,Nucleotide Sequence,RNA Sequence,DNA Sequences,Base Sequences,Nucleotide Sequences,RNA Sequences,Sequence, Base,Sequence, DNA,Sequence, Nucleotide,Sequence, RNA,Sequences, Base,Sequences, DNA,Sequences, Nucleotide,Sequences, RNA
D013294	Lactococcus lactis	A non-pathogenic species of LACTOCOCCUS found in DAIRY PRODUCTS and responsible for the souring of MILK and the production of LACTIC ACID.	Streptococcus lactis,Lactococcus lactis subsp. lactis
D015151	Immunoblotting	Immunologic method used for detecting or quantifying immunoreactive substances. The substance is identified by first immobilizing it by blotting onto a membrane and then tagging it with labeled antibodies.	Dot Immunoblotting,Electroimmunoblotting,Immunoelectroblotting,Reverse Immunoblotting,Immunoblotting, Dot,Immunoblotting, Reverse,Dot Immunoblottings,Electroimmunoblottings,Immunoblottings,Immunoblottings, Dot,Immunoblottings, Reverse,Immunoelectroblottings,Reverse Immunoblottings