♨️♨️ New Models and new Mechanisms of DNA replication and Repair♨️♨️
📣📣The piPolBs as a model for structure-function studies and disclosing new in vivo roles of replicative-like family-B DNA polymerases ♨️
September 2025
Family B DNA polymerases replicate the genome of prokaryotic and eukaryotic cells, viruses and some genetic mobile elements, spanning very different members like human pol ε, pol δ or pol α, as well as archaeal PolB or giant virus replicase.
Primer-independent DNA polymerases group (piPolBs, ref 1) constitutes a third, previously overlooked, clade of family B DNA polymerases (PolBs), along with the RNA-primed (rPolBs) and protein-primed (pPolBs). These DNA polymerases, initially reported by our lab, are faithful replicases endowed with proofreading and strand displacement capacities. Moreover, piPolBs do not display strong sequence requirements for replication initiation and replication origins seem to be selected in a random manner, a property that may be useful for the development of unbiased isothermal DNA amplification. In line with that, we have recently devised a new method for whole (meta)genome amplification-based, based on the combined use of piPolB and Φ29 DNA polymerase that outperforms some commercially available kits in the amplification of high-GC content sequences (ref 4).
In the first project, we will analyze piPolB variants in conserved motifs PolA y PolC in order to (re)define the key amino acids in those motifs in the PolB family.
In a second, alternative project, we will focus on pipolins, a (mostly) integrative genetic mobile element (GME) that codes for piPolBs. We have recently reported that pipolins act as an orthogonal reservoir of (known) defense mechanisms that are actively exchaged with other GMEs, mainly plasmids. We want know to verify if some of the pipolins core genes, including the piPolB itself, have some role in defense against bacteriophages.
This project is funded by a Grants PID2021-123403NB-I00 & PID2024-156454NB-I00 from "Generación del Conocimiento" program of Spanish Research Agency AEI).
Related references:
- Primer-Independent DNA Synthesis by a Family B DNA Polymerase from Self-Replicating Mobile Genetic Elements (Cell Reports, 2017).
- High diversity and variability of pipolins among a wide range of pathogenic Escherichia coli strains (Scientific Reports 2020).
- Engineered viral DNA polymerase with enhanced DNA amplification capacity. A proof-of-concept of isothermal amplification of damaged DNA (Scientific Reports 2020).
- A primer-independent DNA polymerase-based method for competent whole-genome amplification of intermediate to high GC sequences (NAR Genomics & Bioinformatics 2023)
- Pipolins are bimodular platforms that maintain a reservoir of defense systems exchangeable with various bacterial genetic mobile elements (NAR 2024)