Biomaterial Database

Multicopy suppressors, mssA and mssB, of an smbA mutation of Escherichia coli. 1994

K Yamanaka, and T Ogura, and E V Koonin, and H Niki, and S Hiraga

Department of Molecular Cell Biology, Kumamoto University School of Medicine, Japan.

We have isolated and characterized two multicopy suppressors, mssA and mssB, which suppress the cold-sensitive growth phenotype of the smbA2 mutant of Escherichia coli. The mssA gene is located immediately upstream of the rpsA gene (20.5 min). MssA protein was found to be related to nucleoside monophosphate kinases. The mssB gene was found to be identical to the deaD gene (69 min), which encodes a putative RNA helicase. The SmbA protein belongs to the aspartokinase family and probably represents a new, fourth aspartokinase species in E. coli. Expression of the smbA gene is essential for cell growth. The smbA2 mutant shows a pleiotropic phenotype characterized by cold-sensitive growth, hypersensitivity to the detergent sodium dodecyl sulfate, and formation of a translucent segment at midcell or at a pole of the cell when grown at 22 degrees C. In addition, some cellular proteins were either increased or decreased in amount in the smbA2 mutant. SmbA may be a regulatory factor in the expression of a battery of genes. MssA and MssB might also relate to the expression of some of these genes. Multiple copies mssA and mssB suppressed the various phenotypic features of the smbA2 mutant to various extents, suppressing the cold-sensitive growth completely.

UI	MeSH Term	Description	Entries
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
D009154	Mutation	Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.	Mutations
D010641	Phenotype	The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.	Phenotypes
D010770	Phosphotransferases	A rather large group of enzymes comprising not only those transferring phosphate but also diphosphate, nucleotidyl residues, and others. These have also been subdivided according to the acceptor group. (From Enzyme Nomenclature, 1992) EC 2.7.	Kinases,Phosphotransferase,Phosphotransferases, ATP,Transphosphorylase,Transphosphorylases,Kinase,ATP Phosphotransferases
D003080	Cold Temperature	An absence of warmth or heat or a temperature notably below an accustomed norm.	Cold,Cold Temperatures,Temperature, Cold,Temperatures, Cold
D003360	Cosmids	Plasmids containing at least one cos (cohesive-end site) of PHAGE LAMBDA. They are used as cloning vehicles.	Cosmid
D004926	Escherichia coli	A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.	Alkalescens-Dispar Group,Bacillus coli,Bacterium coli,Bacterium coli commune,Diffusely Adherent Escherichia coli,E coli,EAggEC,Enteroaggregative Escherichia coli,Enterococcus coli,Diffusely Adherent E. coli,Enteroaggregative E. coli,Enteroinvasive E. coli,Enteroinvasive Escherichia coli
D005798	Genes, Bacterial	The functional hereditary units of BACTERIA.	Bacterial Gene,Bacterial Genes,Gene, Bacterial
D000595	Amino Acid Sequence	The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.	Protein Structure, Primary,Amino Acid Sequences,Sequence, Amino Acid,Sequences, Amino Acid,Primary Protein Structure,Primary Protein Structures,Protein Structures, Primary,Structure, Primary Protein,Structures, Primary Protein
D001222	Aspartate Kinase	An enzyme that catalyzes the formation of beta-aspartyl phosphate from aspartic acid and ATP. Threonine serves as an allosteric regulator of this enzyme to control the biosynthetic pathway from aspartic acid to threonine. EC 2.7.2.4.	Aspartokinase,Aspartate Kinase I,Aspartate Kinase II,Aspartate Kinase III,Aspartyl Kinase,Kinase I, Aspartate,Kinase II, Aspartate,Kinase III, Aspartate,Kinase, Aspartate,Kinase, Aspartyl