• M.S., 1984, University of Göttingen.
• D.Sci., 1987, University of Göttingen.
• Postdoctoral research: University of Basel, University of Göttingen, University of Georgia.
• Previous faculty appointment, University of Leeds, U.K.

Joined the department in 2000.

Associations: Joint appointment in Department of Biochemistry and Biophysics, Material Sciences Engineering Program, Health Science Center Graduate School of Biomedical Sciences; Director, Microscopy and Imaging Center and Materials Characterization Facility.

Andreas Holzenburg
Professor

3258 TAMU
College Station, TX 77843-3258

Office:
Interdisciplinary Life Sciences Building
Room 1137B
979-845-1164

Lab:
Microscopy Imaging Center

Fax: 979-845-2891
Email: holzen@mic.tamu.edu

Curriculum Vitae

Andreas Holzenburg has employed electron microscopy (EM)/crystallography as a tool for the structural elucidation of (sub)cellular components and biological macromolecules, particularly transmembrane and membrane-associated proteins. The structure determination involves image processing routines and is carried out in conjunction with thorough biochemical characterisations with the view to establish structure-function relationships. Furthermore, the EM approach is often used jointly with other biophysical approaches including X-ray crystallography and spectroscopical methods. As EM is an extremely versatile tool, a number of collaborations on structure-oriented projects have been supported (see publications).

Structure and Function of the Plastid Division Machinery
The Holzenburg lab is interested in the structure, assembly and turnover dynamics of the cytoskeletal tubulin-like FtsZ protein in plant chloroplats. FtsZ plays a pivotal role in the division of prokaryotic cells as well as chloroplasts. One of the functional characteristics of FtsZ is its auto-assembly into a ring-like macromolecular complex called the Z-ring. During cell division, the Z-ring undergoes continuous and rapid remodeling via subunit exchange and constricts at the leading edge of the septum with the simultaneous loss of subunits. Consistent with the endosymbiotic origin of chloroplasts, plants possess nuclear-encoded, plastid-targeted homologues of bacterial FtsZ. However, whereas most prokaryotes, including the cyanobacterial relatives of chloroplasts, have a single form of FtsZ, two structurally distinct FtsZ protein families, FtsZ1 and FtsZ2. Experimental evidence suggests that FtsZ1 and FtsZ2 function in a complex and that their roles are functionally distinct. They are both localized in the stromal compartment of the chloroplast and are always tightly colocalized in immuno-fluorescence labeling experiments. In addition, FtsZ1 seems unable to form long polymers in planta without FtsZ2.

Overall, the molecular mechanism of FtsZ filament assembly and its regulation, the structures of assembled protofilaments, and the structure of the in vivo FtsZ ring in chloroplasts remain poorly understood. Our overall goal is to expand the current model for FtsZ assembly and investigate and define the molecular structure and assembly dynamics of FtsZ rings in chloroplasts of Arabidopsis thaliana with the view to understand chloroplast size control.

Modulation of the size of storage plastids (amyloplasts) and the starch granule size by changing the levels of FtsZ expression is of considerable interest to the starch and biofuel industry, since increased starch granule size improves the wet-milling efficiency and thus the starch yield in staple crops.

1. Johnson CB, Tang LK, Smith AG, Ravichandran A, Luo Z, Vitha S & Holzenburg A (2013) Single Particle Tracking Analysis of the Chloroplast Division Protein FtsZ Anchoring to the Inner Envelope Membrane. Microsc Microanal 19:507-12 Full text
2. Grützner N, Heilmann RM, Stupka KC, Rangachari VR, Weber K, Holzenburg A, Suchodolski JS & Steiner JM (2013) Serum homocysteine and methylmalonic acid concentrations in Chinese Shar-Pei dogs with cobalamin deficiency. Vet J 19:507-12 Full text
3. Weiss TL, Roth R, Goodson C, Vitha S, Black I, Azadi P, Rusch J, Holzenburg A, Devarenne TP & Goodenough U (2012) Colony organization in the green alga Botryococcus braunii (Race B) is specified by a complex extracellular matrix. Eukaryot Cell 11:1424-40 Full text
4. Jeffery J, Holzenburg A & King S (2012) Physical barriers to carotenoid bioaccessibility. Ultrastructure survey of chromoplast and cell wall morphology in nine carotenoid-containing fruits and vegetables. J Sci Food Agric 92:2594-602 Full text
5. Smith AG, Johnson CB, Vitha S & Holzenburg A (2011) Oligomerization of plant FtsZ1 and FtsZ2 plastid division proteins. Arch Biochem Biophys 513:94-101 Full text
6. Arockiasamy A, Aggarwal A, Savva CG, Holzenburg A & Sacchettini JC (2011) Crystal structure of calcium dodecin (Rv0379), from Mycobacterium tuberculosis with a unique calcium-binding site. Protein Sci 20:827-33 Full text
7. White R, Chiba S, Pang T, Dewey JS, Savva CG, Holzenburg A, Pogliano K & Young R (2011) Holin triggering in real time. Proc Natl Acad Sci U S A 108:798-803 Full text
8. Berry J, Savva C, Holzenburg A & Young R (2010) The lambda spanin components Rz and Rz1 undergo tertiary and quaternary rearrangements upon complex formation. Protein Sci 19:1967-77 Full text
9. Weiss TL, Chun HJ, Okada S, Vitha S, Holzenburg A, Laane J & Devarenne TP (2010) Raman spectroscopy analysis of botryococcene hydrocarbons from the green microalga Botryococcus braunii. J Biol Chem 285:32458-66 Full text
10. Dewey JS, Savva CG, White RL, Vitha S, Holzenburg A & Young R (2010) Micron-scale holes terminate the phage infection cycle. Proc Natl Acad Sci U S A 107:2219-23 Full text