Biomaterial Database

Separation of the presynaptic and synaptic phases of homologous pairing promoted by recA protein. 1984

R Kahn, and C M Radding

Homologous pairing of single strands with duplex DNA promoted by recA protein occurred without a lag only when the protein was preincubated with ATP and single-stranded DNA. The rate-limiting presynaptic interaction of recA protein and single strands showed a high temperature coefficient: it proceeded 30 times more slowly at 30 degrees C than at 37 degrees C, whereas synapsis showed a normal temperature coefficient. Thus, the presynaptic phase could be separated experimentally from the rest of the reaction by preincubation of single strands with recA protein and ATP at 37 degrees C, followed by a shift to 30 degrees C before double-stranded DNA was added. The presynaptic phase was an order of magnitude more sensitive to inhibition by ADP than was subsequent strand exchange. Presynaptic complexes that were formed at 37 degrees C decayed only slowly at 30 degrees C, but Escherichia coli single strand binding protein caused complexes to form rapidly at 30 degrees C which indicates that single strand binding protein accelerated the rate of formation of complexes. Preincubation synchronized the initial pairing reaction, and further revealed the rapid formation of nascent heteroduplex DNA 250-300 base pairs in length.

UI	MeSH Term	Description	Entries
D011938	Rec A Recombinases	A family of recombinases initially identified in BACTERIA. They catalyze the ATP-driven exchange of DNA strands in GENETIC RECOMBINATION. The product of the reaction consists of a duplex and a displaced single-stranded loop, which has the shape of the letter D and is therefore called a D-loop structure.	Rec A Protein,RecA Protein,Recombinases, Rec A
D004268	DNA-Binding Proteins	Proteins which bind to DNA. The family includes proteins which bind to both double- and single-stranded DNA and also includes specific DNA binding proteins in serum which can be used as markers for malignant diseases.	DNA Helix Destabilizing Proteins,DNA-Binding Protein,Single-Stranded DNA Binding Proteins,DNA Binding Protein,DNA Single-Stranded Binding Protein,SS DNA BP,Single-Stranded DNA-Binding Protein,Binding Protein, DNA,DNA Binding Proteins,DNA Single Stranded Binding Protein,DNA-Binding Protein, Single-Stranded,Protein, DNA-Binding,Single Stranded DNA Binding Protein,Single Stranded DNA Binding Proteins
D004277	DNA, Single-Stranded	A single chain of deoxyribonucleotides that occurs in some bacteria and viruses. It usually exists as a covalently closed circle.	Single-Stranded DNA,DNA, Single Stranded,Single Stranded DNA
D004279	DNA, Viral	Deoxyribonucleic acid that makes up the genetic material of viruses.	Viral DNA
D000255	Adenosine Triphosphate	An adenine nucleotide containing three phosphate groups esterified to the sugar moiety. In addition to its crucial roles in metabolism adenosine triphosphate is a neurotransmitter.	ATP,Adenosine Triphosphate, Calcium Salt,Adenosine Triphosphate, Chromium Salt,Adenosine Triphosphate, Magnesium Salt,Adenosine Triphosphate, Manganese Salt,Adenylpyrophosphate,CaATP,CrATP,Manganese Adenosine Triphosphate,MgATP,MnATP,ATP-MgCl2,Adenosine Triphosphate, Chromium Ammonium Salt,Adenosine Triphosphate, Magnesium Chloride,Atriphos,Chromium Adenosine Triphosphate,Cr(H2O)4 ATP,Magnesium Adenosine Triphosphate,Striadyne,ATP MgCl2
D001435	Bacteriophages	Viruses whose hosts are bacterial cells.	Phages,Bacteriophage,Phage
D013696	Temperature	The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.	Temperatures