Related Experiment Video
Updated: Aug 16, 2026

Preparation of the Mgm101 Recombination Protein by MBP-based Tagging Strategy
Published on: June 25, 2013
Bacillus subtilis bacteriophage SPP1-encoded gene 34.1 product is a recombination-dependent DNA replication protein
María I Martínez-Jiménez1, Juan C Alonso, Silvia Ayora
1Departamento de Biotecnología Microbiana, Centro Nacional de Biotecnología, CSIC, Darwin 3, Campus de la Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain.
Abstract:
SPP1-encoded replication and recombination proteins, involved in the early steps of the initiation of concatemeric DNA synthesis, have been analyzed. Dimeric G34.1P exonuclease degrades, with a 5' to 3' polarity and in a Mg2+-dependent reaction, preferentially linear double-stranded (ds) DNA rather than single-stranded (ss) DNA. Binding of the replisome organizer, G38P, to its cognate sites (oriDNA) halts the 5' to 3' exonucleolytic activity of G34.1P on dsDNA. The G35P recombinase increases the affinity of G34.1P for dsDNA, and stimulates G34.1P activity on dsDNA, but not on ssDNA. Then, filamented G35P promotes limited strand exchange with a homologous sequence. The ssDNA binding protein, G36P, protects ssDNA from the G34.1P exonuclease activity and stimulates G35P-catalyzed strand exchange. The data presented suggest a model for the role of G34.1P during initiation of sigma replication: G38P bound to oriDNA might halt replication fork progression, and G35P, G34.1P and G36P in concert might lead to the re-establishment of a unidirectional recombination-dependent replication that accounts for the direction of DNA packaging.
More Related Videos
08:14Kinetics of Lagging-strand DNA Synthesis In Vitro by the Bacteriophage T7 Replication Proteins
Published on: February 25, 2017
07:53Visualization and Quantitative Analysis of Genotoxin-Induced PARP1/PARP2 Activation in Cells Using a Fluorescent Fusion Protein-Based Reporter
Published on: April 17, 2026
Related Concept Videos
DNA Bacteriophages
The Replisome
The synthesis of the leading and lagging strands is a highly coordinated process. To explain this, the “Trombone model” was proposed by Bruce Alberts in 1980. The DNA loop formation starts when a primer is synthesized on the parent lagging strand. The loop grows with the...
The Replisome
The synthesis of the leading and lagging strands is a highly coordinated process. To explain this, the “Trombone model” was proposed by Bruce Alberts in 1980. The DNA loop formation starts when a primer is synthesized on the parent lagging strand. The loop grows with the...
Viral Replication: Lytic Cycle
Lysogenic Cycle of Bacteriophages
Viral Replication: Lysogenic Cycle