Justin Kollman

post doctorate

Room N416
Department of Biochemistry & Biophysics
University of California, San Francisco
Mission Bay, Genentech Hall
600 16th St.
San Francisco CA
94143-0448
(415) 502-2930 (Ph)
(415) 476-1902 (Fax)

Structure of γ-tubulin complexes

The microtubule cytoskeleton is organized in part through the control of microtubule nucleation, mediated by γ-tubulin complexes. The focus of my work is to determine the structures of these complexes using three-dimensional electron microscopy. I have determined a low resolution structure of the γ-tubulin small complex (γ-TuSC), the conserved core of the microtubule nucleating machinery. Multiple γ-TuSCs assemble, along with an array of accessory proteins which varies among the major eukaryotic phyla, into γ-tubulin ring complexes (γ-TuRCs). Currently I am determining the structure of the minimal ring complex by cryo-EM reconstruction. I will also be looking at this ring assembly bound to the ends of microtubules, with the goal of elucidating the nature of the interactions of γ-tubulin with microtubule ends. Also of particular interest will be to correlate the dramatic increase in nucleating capacity when γ-TuSC assembles into γ-TuRC with structural changes in the complex.

Publications:

Choy RM, Kollman JM, Zelter A, Davis TN, Agard DA, "Localization and orientation of the gamma-Tubulin Small Complex components using protein tags as labels for single particle EM, J Struct Biol. 2009 Aug 29. (html, pdf)

Polka JK, Kollman JM, Agard DA, Mullins RD, "The Structure and Assembly Dynamics of Plasmid Actin AlfA Imply a Novel Mechanism of DNA Segregation," J Bacteriol. 2009 Aug 7. (html, pdf)

Kollman JM, Pandi L, Sawaya MR, Riley M, Doolittle RF.,"Crystal structure of human fibrinogen", Biochemistry. 2009, 48(18), 3877-86 (abstract).

Kollman JM, Zelter A, Muller EG, Fox B, Rice LM, Davis TN, Agard DA., "The Structure of the γ-Tubulin Small Complex: Implications of Its Architecture and Flexibility for Microtubule Nucleation", Mol Biol Cell. 2008, 19(1), 207-15 (pdf)

Zheng SQ, Kollman JM, Braunfeld MB, Sedat JW, Agard DA, "Automated acquisition of electron microscopic random conical tilt sets," J Struct Biol. 2007 Jan;157(1):148-55.161.(html or pdf).

Doolittle RF, Kollman JM., "Natively unfolded regions of the vertebrate fibrinogen molecule," Proteins. 2006 May 1;63(2):391-7. Review. (abstract)

Kollman JM, Quispe J, "The 17A structure of the 420kDa lobster clottable protein by single particle reconstruction from cryoelectron micrographs," J Struct Biol. 2005 Aug 26; 151(3): pp306-314.(pdf)

Kollman JM, Doolittle RF, "Unusual non-crystallographic symmetry in crystals of a 420 kDa crustacean clottable protein," Acta Crystallogr D Biol Crystallogr. 2005 Apr; 61(Pt 4), pp485-9.(pdf)

Yang Z, Kollman JM, Pandi L, Doolittle RF, "Crystal structure of native chicken fibrinogen at 2.7 A resolution," Biochemistry. 2001 Oct 23; 40(42), pp12515-23. (pdf)

Kollman JM, Doolittle RF, "Determining the relative rates of change for prokaryotic and eukaryotic proteins with anciently duplicated paralogs," J Mol Evol. 2000 Aug; 51(2), pp173-81. (pdf)

Saier MH Jr, Kollman JM, "Is FatP a long-chain fatty acid transporter?" Mol Microbiol. 1999 Aug; 33(3), pp670-2.(pdf)

Tseng TT, Gratwick KS, Kollman J, Park D, Nies DH, Goffeau A, Saier MH Jr., "The RND permease superfamily: an ancient, ubiquitous and diverse family that includes human disease and development proteins," J Mol Microbiol Biotechnol. 1999 Aug;1(1):107-25. Review.  (abstract)