NLM IRP Seminar Schedule
UPCOMING SEMINARS
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April 30, 2024 Wenya Rowe
The conformal central charge of the spin-1/2 XX model derived from long-chain asymptotics -
May 2, 2024 OPEN
TBD -
May 7, 2024 OPEN
TBD -
May 9, 2024 Pascal Mutz
TBD -
May 14, 2024 Stanley Liang
TBD
RECENT SEMINARS
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April 25, 2024 Ermin Hodzic
Condition-Aware Cell Type Deconvolution of Bulk Tissues -
April 23, 2024 OPEN
TBD -
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
Scheduled Seminars on April 11, 2024
Contact NLM_IRP_Seminar_Scheduling@mail.nih.gov with questions about this seminar.
Abstract:
The TnpB proteins are transposon-associated RNA-guided nucleases that are among the most abundant proteins encoded in bacterial and archaeal genomes. TnpB appears to be the evolutionary ancestor of Cas12, the effector nuclease of type V CRISPR-Cas systems. We performed a comprehensive census of TnpBs in archaeal and bacterial genomes and constructed a phylogenetic tree on which we mapped various features of these proteins. We identified numerous cases of apparent recruitment of TnpB for other functions of which the most common is the evolution of type V CRISPR-Cas effectors. In many other cases of more radical exaptation, the catalytic site of the TnpB nuclease is apparently inactivated, suggesting a regulatory function, whereas in others, the activity appears to be retained, indicating that the recruited TnpB functions as a nuclease, for example, as a toxin. These findings demonstrate remarkable evolutionary malleability of the TnpB scaffold and provide extensive opportunities for further exploration of RNA-guided biological systems.