NLM IRP Seminar Schedule
UPCOMING SEMINARS
RECENT SEMINARS
-
April 16, 2024 Jaya Srivastava
Regulatory plasticity of the human genome -
April 11, 2024 Sergey Shmakov
Comprehensive survey of the TnpB RNA-guided nucleases -
April 2, 2024 Yifan Yang
Fairness and Bias in Biomedical AI -
March 28, 2024 Joseph Schafer
Evolutionary selection of proteins with two folds -
March 26, 2024 Sanasar Babajanyan
Microbial diversity and ecological complexity emerging from environmental variation and horizontal gene transfer in a simple mathematical model
Scheduled Seminars on April 25, 2023
Contact NLM_IRP_Seminar_Scheduling@mail.nih.gov with questions about this seminar.
Abstract:
Many bacterial and archaeal viruses encode anti-CRISPR proteins (Acrs) that specifically inhibit CRISPR-Cas systems via various mechanisms. The majority of the Acrs are small, non-enzymatic proteins that abrogate CRISPR activity by binding to Cas effector proteins. The Acrs evolve fast, due to the arms race with the respective CRISPR-Cas systems, which hampers the elucidation of their evolutionary origins by sequence comparison. We performed comprehensive structural modeling using AlphaFold2 for 3693 experimentally characterized and predicted Acrs, followed by comparison to the protein structures in the PDB database. After clustering the Acrs by sequence similarity, 363 high quality structural models were obtained that accounted for 102 Acr families. Structure comparisons allowed identification of homologs for 13 of these families that could be ancestors of the Acrs. Despite the limited extent of structural conservation, the inferred origins of Acrs show distinct trends, in particular, recruitment of toxins and antitoxins and SOS repair system components for the Acr function.