The ribosome, which is responsible for virtually all cellular protein production, is a complex RNA and protein composite consisting of ~50 subunits that cells must assemble rapidly and efficiently to support growth. While biochemical and structural studies of fully mature ribosomes have been crucial in understanding how this machine functions, we still lack a clear understanding of how they are built. The overall goal of this research is to determine how bacterial ribosomes are constructed, and specifically, how a class of helper proteins known as RNA helicases aid in this process. Given its size, highly parallel assembly pathway, and central role in supporting all cellular life, the ribosome is an ideal model system to understand how cells rapidly and efficiently construct molecular machines. This NSF CAREER supported work is key to improving our basic understanding of how such machines are built, and may prove vital in the synthetic biology community’s ongoing endeavors to engineer molecular machines with biotechnology applications. The educational goal of this project is to increase representation of Black biologists in Ph.D. programs by fostering relationships between the Massachusetts Institute of Technology (MIT) and Historically Black Colleges and Universities (HBCU). Specifically, this project will support the training of talented undergraduate students during MIT’s summer and winter extramural research programs and recruitment of “cohorts†of these students to MIT’s Ph.D. programs. This model of early engagement and subsequent enrollment of cohorts of Ph.D. students aims to produce a self-sustaining community of Black scientists at MIT. This program is modeled after successful similar program initiated ~15 years ago between MIT and the University of Puerto Rico, which has created a vibrant community of Puerto Rican scientists at MIT.
The specific scientific goals of this project are to: 1) isolate and determine the composition of bacterial ribosome assembly intermediates bound by ribosome-biogenesis associated helicases; 2) elucidate how these factors function by determining high resolution structures of their ribosomal substrates and products; and 3) investigate how and whether these helicases act in concert to catalyze the assembly process. As ribosome biogenesis is rate-limiting for bacterial cell growth, understanding this process could enable future work to up- or down-regulate ribosome assembly as a means to control bacterial growth, which will broadly impact biotechnology fields including fermentation, bioremediation, and antibiotic development. More broadly, this project will help to define general assembly principles that cells employ to synthesize, fold, and assemble large macromolecular complexes such as the ribosome. Finally, through this project we will improve and employ novel structural biology tools to: 1) directly isolate and structurally characterize complexes from cells in a minimally-perturbative fashion; and 2) determine continuous conformational trajectories for complexes that are undergoing large-scale molecular motions.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
