Crystallographic studies of macromolecular structures

National Institute Of Environmental Health Sciences

Investigators

Linked publications, trials & patents

Abstract

In addition to maintaining and facilitating the use of the X-ray facility for all NIEHS users our lab works on a variety of different biological systems independently as well as in collaboration with other NIEHS scientist to support their research. Our independent research studying heparan/chondroitin sulfate biosynthesis and interactions represents about 25% of our wet lab effort. Brief descriptions of this along with other areas such as allergen/antibody interactions and ribosome biogenesis in support of NIEHS investigators is listed below. Our independent research on heparan sulfate binding proteins and biosynthesis (in collaboration with Dr. Jian Liu at UNC) has been focused on expression of HS binding proteins and screening their ability to crystallize in the presence of HS. To this end we have been able to obtain a crystal structure of one of our targets binding to HS and are examining its biological relevance. We have also continued our work on studying the enzyme pmHS2 from Pasteurella multocida which is utilized in the chemoenzymatic production of heparan sulfate. We are currently seeing if we can design mutants that allow for the utilization of alternative substrates that could simply the synthesis. This represents about 25% of our wet lab efforts. Two brief descriptions below address our work supports other investigators at the institute. 1) Over the past decade, our lab has worked to support the research of Dr. Geoff Mueller in understanding how the structure of allergens relates to the immune response. Over the last couple of years our work has specifically supported his efforts in collaboration with Dr. Sarita Patil at Harvard University to determine allergic patient derived antibody binding sites on the major peanut allergen Ara h 2. This past year Dr. Patil and colleagues identified structurally convergent antibodies arising from different antibody gene rearrangements that bind to Ara h 2. In addition, they identified that germline encoded epitope-specific antibodies that can bind to Ara h 2 occur commonly in the population due to worldwide prevalence of the relevant gene rearrangements. To support this research, we reported on the crystal structure of Ara h 2 binding to the 23P34 mature antibody. This structure was used to understand how these convergent antibodies bind to the 23P34 epitope as well as how the germline might interact with it (Marini-Rapoprt, O. et al Sci Transl med, 2025). 2.) The rixosome is an RNA processing complex that supports ribosome assembly and heterochromatin maintenance by initiating RNA decay. PELP 1 is the central scaffold protein of this complex. In support of Dr. Stanley’s work in ribosome biogenesis, we solved the crystal structure of SENP3 as an MBP fusion binding to a small linear motif from the intrinsically disordered region of PELP1. Our crystal structure reveals how PELP1 allosterically activates the SUMO protease activity (Gordon, J. et al Sci Adv 2025).