Robert P. Gunsalus, Ph.D.


(310) 206-8201
1602 Molecular Science Building

Microbial Biology of Bacteria and Archaea




Professor, Microbiology, Immunology & Molecular Genetics

Faculty member of the UCLA DOE Institute

Faculty the Molecular Biology Institute

Immunity, Microbes & Molecular Pathogenesis GPB Home Area

Genetics & Genomics GPB Home Area

Biochemistry, Biophysics & Structural Biology GPB Home Area



Research Interests

Our research focuses on the molecular biology and physiology of anaerobic microorganisms including the syntrophic bacteria, their associated methanogenic partners plus other archaeal species. They colonize a wide range of habitats on Earth and possess the ability to adapt and grow under varying environmental conditions of temperature, pH and salinity. We are examining how their metabolism, energy harvesting and cell envelope structures adapt by using a variety of genetic, molecular and biochemical approaches.





2) Structure and Function of Microbial Cell Envelopes. We are studying the composition, structure and function of cell envelopes of representative archaeal and bacterial species. Their envelopes often contain a protein coat or surface layer that surrounds the cell membrane and protects it from environmental challenges. We have isolated and characterized the cell envelopes of representative archaeal methanogenic strains of the genus Methanosarcina. The major envelope proteins in each were identified and where many were previously annotated to be “hypothetical proteins”. The most abundant envelope proteins in three of these strains (M. mazei, M.acetivorans and M. barkeri) were structurally characterized. Following synthesis in the cytoplasm, each protein is then post-translationally modified, exported to the cell surface and assembled into an outermost cell layer or coat that surrounds and protects the cytoplasmic membrane. Recent studies have also provided the first high resolution three-dimensional structure of an archaeal S-layer protein. These investigations provide insights regarding the ability of these archaea to adapt to diverse conditions of temperature, pH, salinity, pressure and light.


Dr. Gunsalus is a Professor in the Department of Microbiology, Immunology, and Molecular Genetics at the University of California, Los Angeles within the School of Life Sciences and the David Geffen School of Medicine at UCLA. His B.S. degree is in Microbiology and in Chemistry from the South Dakota State University. He received his PhD in Microbial Biochemistry from the University of Illinois at Urbana Champaign working with Dr. Ralph S. Wolfe. Prior to coming to UCLA, he did postdoctoral work at Stanford University in Palo Alto working in the areas of Molecular Biology with Drs. Charles Yanofsky and Robert D. Simoni.


Recent Publications


Poweleit, N., P. Ge, H.H. Nguyen, R.R. Ogorzalek Loo,  R. Gunsalus, and Z.H. Zhou. CryoEM structure of the Methanospirillum hungatei archaellum reveals structural features distinct from the bacterial flagellum and type IV pilus. Nature Microbiology. 2016; (2): 16,264.


Gunsalus, R.P., L.E. Cook, B. Crable, L. Rohlin, E. McDonald, H. Mouttaki, J.R. Sieber, N. Poweleit, Z.H. Zhou, A.L. Lapidus H.E. Daligault, M. Land, P. Gilna, N. Ivanova, N. Kyrpides, D.E. Culley and M.J. McInerney. Complete genome sequence of Methanospirillum hungatei type strain JF1. Standards in Genomic Sciences. 2016; 11(4): 2.


Toso D.B, M.J. Javed, E. Czornyj, R.P. Gunsalus, and Z.H. Zhou. Discovery and Characterization of Iron Sulfide and Polyphosphate Bodies Coexisting in Archaeoglobus fulgidus Cells. Archaea. 2016(4): 4706532.


Sieber J.R., B.R. Crable, C.S. Sheik, G.B. Hurst, L. Rohlin, R.P. Gunsalus and M.J. McInerney. Proteomic analysis reveals metabolic and regulatory systems involved in the syntrophic and axenic lifestyle of Syntrophomonas wolfei. Frontiers in Microbiology. 2015; 6(3):1-9.


Briegel, A., D.R. Ortega, A.N. Huang, C.M. Oikonomou, R.P. Gunsalus  and G.J. Jensen. Structural conservation of chemotaxis machinery across Archaea and Bacteria. Environmental Microbiology reports. 2015; 7(3): 414-9.


Katsir, G., M. Jarvis, M. Phillips, Z. Ma, and R.P. Gunsalus. The Escherichia coli NarL receiver domain regulates transcription through promoter specific functions. BMC Microbiology. 2015; 15(1): 174.


Arbing, M.A., S. Chan, A. Shin, T. Phan, C.J. Ahn, L. Rohlin, and R.P. Gunsalus. Structure of the surface layer of the methanogenic archaean Methanosarcina acetivorans. Proceedings of the National Academy of Sciences of the United States of America. 2012; 109(29): 11812-7.


Sieber, J.R. M.J. McInerney and R.P. Gunsalus. Genomic Insights into Syntrophy: The Paradigm for Anaerobic Metabolic Cooperation. Annual Review of Microbiology. 2012; 66:429-52


Rohlin, L., and R.P. Gunsalus. Carbon-dependent control of electron transfer and central carbon pathway genes for methane biosynthesis in the Archaean, Methanosarcina acetivorans strain C2A. BMC Microbiology. 2010; 10:62.


Francoleon D.R., P. Boontheung, Y. Yang, U.M. Kim, J.A. Ytterberg, P.A. Denny, P.C. Denny, J.A. Loo, R.P. Gunsalus and R.O. Ogorzalek Loo. S-layer, surface-accessible, and concanavalin A binding proteins of Methanosarcina acetivorans and Methanosarcina mazei. Journal of Proteome Research. 2009; 8(4): 1972-82.


McInerney, M.J. L. Rohlin, H. Mouttaki, U.M. Kim. R.S. Krupp, L. Rios-Hernandez, J.R. Sieber, C.G. Struchtemeyer, A. Bhattacharyya, J.W. Campbell, and R.P. Gunsalus. The genome of Syntrophus aciditrophicus: life at the thermodynamic limit of microbial growth. Proceedings of the National Academy of Sciences of the United States of America. 2007; 104(18): 7600-5.


Lab Members

Lauren Cook – Graduate Student

Muhammad Usman Ahmad – Visiting Graduate Student

Anzhou Ma, – Visiting Professor

Farzaneh Sedighian – Research Assistant

Scott Turnbull – Undergraduate Researcher

Alex Griffith – Undergraduate Researcher

Kevin Yin– Undergraduate Researcher

Dorothy Kenny – Undergraduate Researcher




UCLA Molecular Biology Institute


UCLA DOE Institute of Genomics and Proteomics


UCLA Medical School Biosciences


EcoCyc – the Escherichia coli protein gene database


Departmental Graduate Studies in Microbiology