A conservative amino acid mutation in the chromosome-encoded dihydrofolate reductase confers trimethoprim resistance in Streptococcus pneumoniae. 1998

A Pikis, and J A Donkersloot, and W J Rodriguez, and J M Keith
Vaccine and Therapeutic Development Section, Oral Infection and Immunity Branch, National Institute of Dental Research, National Institutes of Health, Bethesda, Maryland 20892-4350, USA. apikis@yoda.nidr.nih.gov

Multidrug-resistant Streptococcus pneumoniae strains have emerged over the past decade at an alarming rate. The molecular mechanism of trimethoprim resistance was investigated in 5 pneumococcal strains isolated in the Washington, DC, area from patients with invasive infections. Cloning and sequencing of the trimethoprim resistance determinant from these pneumococci indicated that an altered chromosome-encoded dihydrofolate reductase (DHFR) was responsible for the observed resistance. Comparison of DHFR sequences from pneumococcal strains with various susceptibilities to trimethoprim, together with site-directed mutagenesis, revealed that substitution of isoleucine-100 with a leucine residue resulted in trimethoprim resistance. Hydrogen bonding between the carbonyl oxygen of isoleucine-100 and the 4-amino group of trimethoprim is proposed to play a critical role in the inhibition of DHFR by trimethoprim. This enzyme-substrate model should facilitate the design of new antibacterial agents with improved activity against S. pneumoniae.

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
D002876 Chromosomes, Bacterial Structures within the nucleus of bacterial cells consisting of or containing DNA, which carry genetic information essential to the cell. Bacterial Chromosome,Bacterial Chromosomes,Chromosome, Bacterial
D004269 DNA, Bacterial Deoxyribonucleic acid that makes up the genetic material of bacteria. Bacterial DNA
D004352 Drug Resistance, Microbial The ability of microorganisms, especially bacteria, to resist or to become tolerant to chemotherapeutic agents, antimicrobial agents, or antibiotics. This resistance may be acquired through gene mutation or foreign DNA in transmissible plasmids (R FACTORS). Antibiotic Resistance,Antibiotic Resistance, Microbial,Antimicrobial Resistance, Drug,Antimicrobial Drug Resistance,Antimicrobial Drug Resistances,Antimicrobial Resistances, Drug,Drug Antimicrobial Resistance,Drug Antimicrobial Resistances,Drug Resistances, Microbial,Resistance, Antibiotic,Resistance, Drug Antimicrobial,Resistances, Drug Antimicrobial
D006801 Humans Members of the species Homo sapiens. Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
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
D000900 Anti-Bacterial Agents Substances that inhibit the growth or reproduction of BACTERIA. Anti-Bacterial Agent,Anti-Bacterial Compound,Anti-Mycobacterial Agent,Antibacterial Agent,Antibiotics,Antimycobacterial Agent,Bacteriocidal Agent,Bacteriocide,Anti-Bacterial Compounds,Anti-Mycobacterial Agents,Antibacterial Agents,Antibiotic,Antimycobacterial Agents,Bacteriocidal Agents,Bacteriocides,Agent, Anti-Bacterial,Agent, Anti-Mycobacterial,Agent, Antibacterial,Agent, Antimycobacterial,Agent, Bacteriocidal,Agents, Anti-Bacterial,Agents, Anti-Mycobacterial,Agents, Antibacterial,Agents, Antimycobacterial,Agents, Bacteriocidal,Anti Bacterial Agent,Anti Bacterial Agents,Anti Bacterial Compound,Anti Bacterial Compounds,Anti Mycobacterial Agent,Anti Mycobacterial Agents,Compound, Anti-Bacterial,Compounds, Anti-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
D013296 Streptococcus pneumoniae A gram-positive organism found in the upper respiratory tract, inflammatory exudates, and various body fluids of normal and/or diseased humans and, rarely, domestic animals. Diplococcus pneumoniae,Pneumococcus

Related Publications

A Pikis, and J A Donkersloot, and W J Rodriguez, and J M Keith
February 1997, Journal of molecular biology,
A Pikis, and J A Donkersloot, and W J Rodriguez, and J M Keith
November 1997, Antimicrobial agents and chemotherapy,
A Pikis, and J A Donkersloot, and W J Rodriguez, and J M Keith
April 2001, Antimicrobial agents and chemotherapy,
A Pikis, and J A Donkersloot, and W J Rodriguez, and J M Keith
April 1993, Journal of medical microbiology,
A Pikis, and J A Donkersloot, and W J Rodriguez, and J M Keith
October 1988, The Journal of antimicrobial chemotherapy,
A Pikis, and J A Donkersloot, and W J Rodriguez, and J M Keith
July 1990, Journal of medical microbiology,
A Pikis, and J A Donkersloot, and W J Rodriguez, and J M Keith
April 1990, Journal of general microbiology,
A Pikis, and J A Donkersloot, and W J Rodriguez, and J M Keith
July 2013, Biochemistry,
A Pikis, and J A Donkersloot, and W J Rodriguez, and J M Keith
January 1992, Journal of medical microbiology,
Copied contents to your clipboard!