Biomaterial Database

Role of phenylalanine-327 in the closure of loop 6 of ribulosebisphosphate carboxylase/oxygenase from Rhodospirillum rubrum. 1993

A G Day, and P Chène, and A R Fersht

Department of Chemistry, University of Cambridge, England.

Phenylalanine-327 of ribulosebisphosphate carboxylase/oxygenase (rubisco) from Rhodospirillum rubrum was mutated to tryptophan, leucine, valine, alanine, and glycine, and was also deleted. The least active mutant, the deletion mutant, exhibits less than 0.5% of the carboxylase activity of the wild-type enzyme. Steady-state kinetic analysis of F327-->Leu, Val, Ala, Gly mutant enzymes reveals that kcat and the CO2/O2 specificity are unchanged while Km(RuBP) (RuBP = ribulose 1,5-bisphosphate) is drastically increased. The mutant enzyme with the highest value for Km(RuBP),Phe327-->Gly, shows a 165-fold increase (1160 microM compared to 7 microM for the wild-type). The increase in Km(RuBP) suggests an alteration of the ratio kon/koff for RuBP. A longer hydrophobic lateral chain and/or the presence of an aromatic ring in the wild-type enzyme and the Phe327-->Trp mutant enzyme could explain a better packing of loop 6 in the closed conformation and thus a tighter binding of RuBP at the active site.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
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
D010649	Phenylalanine	An essential aromatic amino acid that is a precursor of MELANIN; DOPAMINE; noradrenalin (NOREPINEPHRINE), and THYROXINE.	Endorphenyl,L-Phenylalanine,Phenylalanine, L-Isomer,L-Isomer Phenylalanine,Phenylalanine, L Isomer
D011487	Protein Conformation	The characteristic 3-dimensional shape of a protein, including the secondary, supersecondary (motifs), tertiary (domains) and quaternary structure of the peptide chain. PROTEIN STRUCTURE, QUATERNARY describes the conformation assumed by multimeric proteins (aggregates of more than one polypeptide chain).	Conformation, Protein,Conformations, Protein,Protein Conformations
D011994	Recombinant Proteins	Proteins prepared by recombinant DNA technology.	Biosynthetic Protein,Biosynthetic Proteins,DNA Recombinant Proteins,Recombinant Protein,Proteins, Biosynthetic,Proteins, Recombinant DNA,DNA Proteins, Recombinant,Protein, Biosynthetic,Protein, Recombinant,Proteins, DNA Recombinant,Proteins, Recombinant,Recombinant DNA Proteins,Recombinant Proteins, 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
D001665	Binding Sites	The parts of a macromolecule that directly participate in its specific combination with another molecule.	Combining Site,Binding Site,Combining Sites,Site, Binding,Site, Combining,Sites, Binding,Sites, Combining
D012247	Rhodospirillum rubrum	Vibrio- to spiral-shaped phototrophic bacteria found in stagnant water and mud exposed to light.
D012273	Ribulose-Bisphosphate Carboxylase	A carboxy-lyase that plays a key role in photosynthetic carbon assimilation in the CALVIN-BENSON CYCLE by catalyzing the formation of 3-phosphoglycerate from ribulose 1,5-biphosphate and CARBON DIOXIDE. It can also utilize OXYGEN as a substrate to catalyze the synthesis of 2-phosphoglycolate and 3-phosphoglycerate in a process referred to as photorespiration.	Carboxydismutase,Ribulose Biphosphate Carboxylase-Oxygenase,Ribulose Diphosphate Carboxylase,Ribulosebiphosphate Carboxylase,Rubisco,1,5-Biphosphate Carboxylase-Oxygenase,Ribulose Biphosphate Carboxylase,Ribulose Bisphosphate Carboxylase,Ribulose-1,5-Biphosphate Carboxylase,Ribulose-1,5-Biphosphate Carboxylase-Oxygenase,Ribulose-1,5-Bisphosphate Carboxylase Small-Subunit,Ribulose-Bisphosphate Carboxylase Large Subunit,Ribulose-Bisphosphate Carboxylase Small Subunit,Rubisco Small Subunit,1,5 Biphosphate Carboxylase Oxygenase,Biphosphate Carboxylase-Oxygenase, Ribulose,Carboxylase Small-Subunit, Ribulose-1,5-Bisphosphate,Carboxylase, Ribulose Bisphosphate,Carboxylase, Ribulose Diphosphate,Carboxylase, Ribulose-1,5-Biphosphate,Carboxylase, Ribulose-Bisphosphate,Carboxylase, Ribulosebiphosphate,Carboxylase-Oxygenase, 1,5-Biphosphate,Carboxylase-Oxygenase, Ribulose Biphosphate,Carboxylase-Oxygenase, Ribulose-1,5-Biphosphate,Diphosphate Carboxylase, Ribulose,Ribulose 1,5 Biphosphate Carboxylase,Ribulose 1,5 Biphosphate Carboxylase Oxygenase,Ribulose 1,5 Bisphosphate Carboxylase Small Subunit,Ribulose Biphosphate Carboxylase Oxygenase,Ribulose Bisphosphate Carboxylase Large Subunit,Ribulose Bisphosphate Carboxylase Small Subunit,Small Subunit, Rubisco,Small-Subunit, Ribulose-1,5-Bisphosphate Carboxylase
D016297	Mutagenesis, Site-Directed	Genetically engineered MUTAGENESIS at a specific site in the DNA molecule that introduces a base substitution, or an insertion or deletion.	Mutagenesis, Oligonucleotide-Directed,Mutagenesis, Site-Specific,Oligonucleotide-Directed Mutagenesis,Site-Directed Mutagenesis,Site-Specific Mutagenesis,Mutageneses, Oligonucleotide-Directed,Mutageneses, Site-Directed,Mutageneses, Site-Specific,Mutagenesis, Oligonucleotide Directed,Mutagenesis, Site Directed,Mutagenesis, Site Specific,Oligonucleotide Directed Mutagenesis,Oligonucleotide-Directed Mutageneses,Site Directed Mutagenesis,Site Specific Mutagenesis,Site-Directed Mutageneses,Site-Specific Mutageneses