Dr. Naima Gabriela Sharaf graduated from the University of North Carolina at Chapel Hill with a bachelor's degree in chemistry. She earned her Ph.D. in Dr. Angela Gronenborn's lab at the University of Pittsburgh, where she investigated inhibitor-induced conformational changes in HIV-1 reverse transcriptase using fluorine solution NMR. She completed her postdoctoral training at Caltech in Dr. Doug Rees' lab, where she used x-ray crystallography and single-particle cryo-EM to characterize the structure and function of the Neisseria meningitidis methionine ABC transport system. This study sparked Dr. Sharaf's current interest in lipoproteins, specifically their roles in bacterial physiology and potential in vaccine design. The Sharaf Lab conducts research that bridges biochemistry, biology, microbiology, and immunology in order to translate lipoprotein research into therapeutics.
Current Research and Scholarly Interests
Proteins embedded in bacteria's cell envelope conduct a variety of vital tasks, including signaling, nutrition uptake, and virulence factor export. Understanding the structure and functions of these proteins is essential for developing new therapies. The lab is currently focused on ABC transporters and lipoproteins of Gram-negative bacteria. Our long-term goal is to transfer fundamental lipoprotein research into new treatments.
- Frontiers in Biology
BIO 301 (Aut, Win)
- Integrative and Experimental Microbiology
BIO 120, BIO 220 (Spr)
- Independent Studies (4)
- Prior Year Courses
Characterization of the ABC methionine transporter from Neisseria meningitidis reveals that lipidated MetQ is required for interaction
NmMetQ is a substrate-binding protein (SBP) from Neisseria meningitidis that has been identified as a surface-exposed candidate antigen for meningococcal vaccines. However, this location for NmMetQ challenges the prevailing view that SBPs in Gram-negative bacteria are localized to the periplasmic space to promote interaction with their cognate ABC transporter embedded in the bacterial inner membrane. To elucidate the roles of NmMetQ, we characterized NmMetQ with and without its cognate ABC transporter (NmMetNI). Here, we show that NmMetQ is a lipoprotein (lipo-NmMetQ) that binds multiple methionine analogs and stimulates the ATPase activity of NmMetNI. Using single-particle electron cryo-microscopy, we determined the structures of NmMetNI in the presence and absence of lipo-NmMetQ. Based on our data, we propose that NmMetQ tethers to membranes via a lipid anchor and has dual function and localization, playing a role in NmMetNI-mediated transport at the inner membrane and moonlighting on the bacterial surface.
View details for DOI 10.7554/eLife.69742
View details for Web of Science ID 000693095000001
View details for PubMedID 34409939
View details for PubMedCentralID PMC8416018