Biomaterial Database

Mutagenesis studies of the F1F0 ATP synthase b subunit membrane domain. 2003

Andrew W Hardy, and Tammy Bohannon Grabar, and Deepa Bhatt, and Brian D Cain

Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, Florida, USA.

A homodimer of b subunits constitutes the peripheral stalk linking the F1 and F0 sectors of the Escherichia coli ATP synthase. Each b subunit has a single-membrane domain. The constraints on the membrane domain have been studied by systematic mutagenesis. Replacement of a segment proximal to the cytoplasmic side of the membrane had minimal impact on F1F0 ATP synthase. However, multiple substitutions on the periplasmic side resulted in defects in assembly of the enzyme complex. These mutants had insufficient oxidative phosphorylation to support growth, and biochemical studies showed little F1F0 ATPase and no detectable ATP-driven proton pumping activity. Expression of the b(N2A,T6A,Q10A) subunit was also oxidative phosphorylation deficient, but the b(N2A,T6A,Q10A) protein was incorporated into an F1F0 complex. Single amino acid substitutions had minimal reductions in F1F0 ATP synthase function. The evidence suggests that the b subunit membrane domain has several sites of interaction contributing to assembly of F0, and that these interactions are strongest on the periplasmic side of the bilayer.

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
D010085	Oxidative Phosphorylation	Electron transfer through the cytochrome system liberating free energy which is transformed into high-energy phosphate bonds.	Phosphorylation, Oxidative,Oxidative Phosphorylations,Phosphorylations, Oxidative
D002462	Cell Membrane	The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.	Plasma Membrane,Cytoplasmic Membrane,Cell Membranes,Cytoplasmic Membranes,Membrane, Cell,Membrane, Cytoplasmic,Membrane, Plasma,Membranes, Cell,Membranes, Cytoplasmic,Membranes, Plasma,Plasma Membranes
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
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
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
D016296	Mutagenesis	Process of generating a genetic MUTATION. It may occur spontaneously or be induced by MUTAGENS.	Mutageneses
D017434	Protein Structure, Tertiary	The level of protein structure in which combinations of secondary protein structures (ALPHA HELICES; BETA SHEETS; loop regions, and AMINO ACID MOTIFS) pack together to form folded shapes. Disulfide bridges between cysteines in two different parts of the polypeptide chain along with other interactions between the chains play a role in the formation and stabilization of tertiary structure.	Tertiary Protein Structure,Protein Structures, Tertiary,Tertiary Protein Structures
D021122	Protein Subunits	Single chains of amino acids that are the units of multimeric PROTEINS. Multimeric proteins can be composed of identical or non-identical subunits. One or more monomeric subunits may compose a protomer which itself is a subunit structure of a larger assembly.	Protomers,Protein Subunit,Protomer,Subunit, Protein,Subunits, Protein
D025261	Mitochondrial Proton-Translocating ATPases	Proton-translocating ATPases responsible for ADENOSINE TRIPHOSPHATE synthesis in the MITOCHONDRIA. They derive energy from the respiratory chain-driven reactions that develop high concentrations of protons within the intermembranous space of the mitochondria.	Electron Transport Complex V,Mitochondrial ATP Synthase,Respiratory Complex V,Mitochondrial ATP Synthases,Mitochondrial F(1)F(0) ATPase,ATP Synthase, Mitochondrial,ATP Synthases, Mitochondrial,ATPases, Mitochondrial Proton-Translocating,Mitochondrial Proton Translocating ATPases,Proton-Translocating ATPases, Mitochondrial