Accelerated Evolution by Diversity-Generating Retroelements.
Annu Rev Microbiol
; 76: 389-411, 2022 09 08.
Article
em En
| MEDLINE
| ID: mdl-35650669
ABSTRACT
Diversity-generating retroelements (DGRs) create vast amounts of targeted, functional diversity by facilitating the rapid evolution of ligand-binding protein domains. Thousands of DGRs have been identified in bacteria, archaea, and their respective viruses. They are broadly distributed throughout the microbial world, with enrichment observed in certain taxa and environments. The diversification machinery works through a novel mechanism termed mutagenic retrohoming, whereby nucleotide sequence information is copied from an invariant DNA template repeat (TR) into an RNA intermediate, selectively mutagenized at TR adenines during cDNA synthesis by a DGR-encoded reverse transcriptase, and transferred to a variable repeat (VR) region within a variable-protein gene (54). This unidirectional flow of information leaves TR-DNA sequences unmodified, allowing for repeated rounds of mutagenic retrohoming to optimize variable-protein function. DGR target genes are often modular and can encode one or more of a wide variety of discrete functional domains appended to a diversifiable ligand-binding motif. Bacterial variable proteins often localize to cellsurfaces, although a subset appear to be cytoplasmic, while phage-encoded DGRs commonly diversify tail fiber-associated receptor-binding proteins. Here, we provide a comprehensive review of the mechanism and consequences of accelerated protein evolution by these unique and beneficial genetic elements.
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Texto completo:
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Bacteriófagos
/
Retroelementos
Tipo de estudo:
Prognostic_studies
Idioma:
En
Revista:
Annu Rev Microbiol
Ano de publicação:
2022
Tipo de documento:
Article