Biomaterial Database

An insertional point mutation inactivates NolR repressor in Rhizobium meliloti 1021. 1994

M Cren, and A Kondorosi, and E Kondorosi

Institut des Sciences Végétales, Centre National de la Recherche Scientifique, Gif-sur-Yvette, France.

In the majority of Rhizobium meliloti isolates, nod gene expression is controlled by NolR, but this is not the case in a few strains including the widely used laboratory strain 1021. In 1021, the lack of NolR function was shown to be due to a single insertional mutation in the C-terminal coding sequence which abolished the DNA-binding ability, though the helix-turn-helix motif remained intact. This indicates that the C-terminal part of the protein is also essential for DNA binding. We conclude that in this species, control of nod gene expression involves NolR and strain 1021 represents an exception in which the NolR function was lost by a single event.

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
D011485	Protein Binding	The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.	Plasma Protein Binding Capacity,Binding, Protein
D012045	Regulatory Sequences, Nucleic Acid	Nucleic acid sequences involved in regulating the expression of genes.	Nucleic Acid Regulatory Sequences,Regulatory Regions, Nucleic Acid (Genetics),Region, Regulatory,Regions, Regulatory,Regulator Regions, Nucleic Acid,Regulatory Region,Regulatory Regions
D012097	Repressor Proteins	Proteins which maintain the transcriptional quiescence of specific GENES or OPERONS. Classical repressor proteins are DNA-binding proteins that are normally bound to the OPERATOR REGION of an operon, or the ENHANCER SEQUENCES of a gene until a signal occurs that causes their release.	Repressor Molecules,Transcriptional Silencing Factors,Proteins, Repressor,Silencing Factors, Transcriptional
D004269	DNA, Bacterial	Deoxyribonucleic acid that makes up the genetic material of bacteria.	Bacterial DNA
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
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
D016254	Mutagenesis, Insertional	Mutagenesis where the mutation is caused by the introduction of foreign DNA sequences into a gene or extragenic sequence. This may occur spontaneously in vivo or be experimentally induced in vivo or in vitro. Proviral DNA insertions into or adjacent to a cellular proto-oncogene can interrupt GENETIC TRANSLATION of the coding sequences or interfere with recognition of regulatory elements and cause unregulated expression of the proto-oncogene resulting in tumor formation.	Gene Insertion,Insertion Mutation,Insertional Activation,Insertional Mutagenesis,Linker-Insertion Mutagenesis,Mutagenesis, Cassette,Sequence Insertion,Viral Insertional Mutagenesis,Activation, Insertional,Activations, Insertional,Cassette Mutagenesis,Gene Insertions,Insertion Mutations,Insertion, Gene,Insertion, Sequence,Insertional Activations,Insertional Mutagenesis, Viral,Insertions, Gene,Insertions, Sequence,Linker Insertion Mutagenesis,Mutagenesis, Linker-Insertion,Mutagenesis, Viral Insertional,Mutation, Insertion,Mutations, Insertion,Sequence Insertions
D016962	Sinorhizobium meliloti	A species of gram-negative, aerobic bacteria that causes formation of root nodules on some, but not all, types of sweet clover, MEDICAGO SATIVA, and fenugreek.	Ensifer meliloti,Rhizobium meliloti
D017354	Point Mutation	A mutation caused by the substitution of one nucleotide for another. This results in the DNA molecule having a change in a single base pair.	Mutation, Point,Mutations, Point,Point Mutations