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Prof. Dr. Christian Hammann (External)
Prof. Dr.
Adjunct Professor
School of Science
Life Sciences & Chemistry

Campus Ring 1 28759 Bremen Germany

+49 421 200-3249
c.hammann [at]
Research II, Room 119
Fellowships and Awards: 
2015, 2019Teacher of the Year
2008-2012DFG Heisenberg Stipend
2001Karl-Lohmann-Prize of the GBM, Lohmann Lecture
1999EMBO Fellowship
1997-1999Stipend of the EU Biotechnology program


Membership in Scientific Societies
American Association for the Advancement of Science (AAAS)               
Deutscher Hochschulverband (DHV)         
Gesellschaft Deutscher Chemiker (GDCh)               
Gesellschaft für Biochemie und Molekularbiologie (GBM)                     
Gesellschaft für Genetik (GfG)                 
RNA Society             
Science Bridge e.V.                        
Vereinigung für Allgemeine und Angewandte Mikrobiologie (VAAM)                  



Since 2016

Erber, L., Hoffmann, A., Fallmann, J., Hagedorn, M., Hammann, C., Stadler, P., Betat, H., Prohaska, S., and Mörl, M. (2020) Unusual occurrence of two bona-fide CCA-adding enzymes in Dictyostelium discoideum. International Journal of Molecular Sciences, in press

Schäck, M.A., Jablonski, K.P., Gräf, S., Klassen, R., Schaffrath, R., Kellner, S., and Hammann, C. (2020) Eukaryotic life without tQCUG: the role of Elongator-dependent tRNA modifications in Dictyostelium discoideum. Nucleic Acids Research, in press

Malicki, M., Spaller, T., Winckler, T., and Hammann, C. (2020) DIRS retrotransposons amplify via linear, single-stranded cDNA intermediates. Nucleic Acids Research, 48, 4230-4243.

Weinberg, C.E., Weinberg, Z., and Hammann, C. (2019) Novel ribozymes: discovery, catalytic mechanisms, and the quest to understand biological function. Nucleic Acids Research, 47, 9480-9494.

Borland, K., Diesend, J., Ito-Kureha, T., Heissmeyer, V., Hammann, C., Buck, A.H., Michalakis, S., and Kellner, S. (2019) Production and Application of Stable Isotope-Labeled Internal Standards for RNA Modification Analysis. Genes, 10, 26.

Diesend, J., Kruse, J., Hagedorn, M., and Hammann, C. (2018) Amoebae, Giant Viruses, and Virophages Make Up a Complex, Multilayered Threesome. Front Cell Infect Microbiol, 7, 527.

Malicki, M., Iliopoulou, M., and Hammann, C. (2017) Retrotransposon Domestication and Control in Dictyostelium discoideum. Frontiers in Microbiology, 8, 1869.

Hammann, C. (2016) Hammerhead ribozymes going viral. Genome Biology 17, 136

Kruse, J., Meier, D., Zenk, F., Rehders, M., Nellen, W., and Hammann, C. (2016) The protein domains of the Dictyostelium microprocessor that are required for correct subcellular localization and for microRNA maturation. RNA Biology 13, 1000-1010

Meier, D., Kruse, J., Buttlar, J., Friedrich, M., Zenk, F., Boesler, B., Förstner, K., Hammann, C., and Nellen, W. (2016) Analysis of the microprocessor in Dictyostelium: the role of RbdB, a dsRNA binding protein. PLoS Genetics 12, e1006057

Duchardt-Ferner, E., Gottstein-Schmidtke, S. R., Weigand, J. E., Ohlenschlager, O., Wurm, J. P., Hammann, C., Suess, B., and Wohnert, J. (2016) What a Difference an OH Makes: Conformational Dynamics as the Basis for the Ligand Specificity of the Neomycin-Sensing Riboswitch. Angewandte Chemie Int Ed Engl 55, 1527-1530



Boesler, B., Meier, D., Foerstner, K. U., Friedrich, M., Hammann, C., Sharma, C. M., and Nellen, W. (2014) Argonaute proteins affect siRNA levels and accumulation of a novel extrachromosomal DNA from the Dictyostelium retrotransposon DIRS-1. Journal of Biological Chemistry 289, 35124-35138

Schmith, A., Spaller, T., Gaube, F., Fransson, A., Boesler, B., Ojha, S., Nellen, W., Hammann, C., Soderbom, F., and Winckler, T. (2015) A host factor supports retrotransposition of the TRE5-A population in Dictyostelium cells by suppressing an Argonaute protein. Mobile DNA 6, 14

Wiegand, S., Meier, D., Seehafer, C., Malicki, M., Hofmann, P., Schmith, A., Winckler, T., Foldesi, B., Boesler, B., Nellen, W., Reimegard, J., Kaller, M., Hallman, J., Emanuelsson, O., Avesson, L., Soderbom, F., and Hammann, C. (2014) The Dictyostelium discoideum RNA-dependent RNA polymerase RrpC silences the centromeric retrotransposon DIRS-1 post-transcriptionally and is required for the spreading of RNA silencing signals. Nucleic Acids Research 42, 3330-3345

Saponaro, A., Pauleta, S., Cantini, F., Matzapetakis, M., Hammann, C., Donadoni, C., Hu, L., Thiel, G., Banci, L., Santoro, B. and Moroni, A. (2014)
Structural basis for the mutual antagonism of cAMP and TRIP8b in regulating HCN channel function.
Proceedings of the National Academy of Sciences USA, 111, 14577-14582

Bajaj, P. and Hammann, C. (2014)
Characterization of Hairpin Ribozyme Reactions.
Methods in Molecular Biology, 1103, 97-111

Kalweit, A. and Hammann C. (2013)
G17-modified Hammerhead Ribozymes are active in vitro and in vivo.
RNA, 19, 1505-1604

Wiegand S. and Hammann, C. (2013)
The 5′ spreading of small RNAs in Dictyostelium discoideum depends on the RNA-dependent RNA polymerase RrpC and on the dicer-related nuclease DrnB.
 PLOS ONE, 8(5):e64804

Hofmann, P., Kruse, J. and Hammann, C. (2013)
Transcript localization in Dictyostelium discoideum cells by RNA FISH.
 Methods in Molecular Biology, 983, 311-323

Hammann, C. and Steger, G. (2012)
Viroid-specific small RNA in plant disease.
 RNA Biology, 9, 809-819

Hammann, C., Luptak, A., Perreault, J. and de la Pena, M. (2012)
The ubiquitous hammerhead ribozyme.
 RNA, 18, 871-885

Kalweit, A., Przybilski, R., Seehafer C., De la Peña, M. and Hammann C. (2012).
Characterization of Hammerhead Ribozyme reactions.
 Methods in Molecular Biology, 848, 5-20

Gahura O., Hammann C., Valentova A., Puta F. and Folk P. (2011).
Secondary structure is required for 3′ splice site recognition in yeast.
 Nucleic Acids Research 39, 9756-9767

Hammann C, Hartmann RK, Helm M, Klostermeier D, Marchfelder A, Suess B and Vörtler S. (2011).
Regulatory RNAs and beyond.
 EMBO Reports 12, 751-753

Bajaj, P., Steger, G. and Hammann, C. (2011).
Sequence elements outside the catalytic core of natural hairpin ribozymes modulate the reactions differentially.
 Biological Chemistry, 392, 593-600

Boesler, C., Kruse, J., Soderbom, F. and Hammann, C. (2011).
Sequence and generation of mature ribosomal RNA transcripts in Dictyostelium discoideum.
 Journal of Biological Chemistry, 286, 17693-17703

Weigand, J.E., Schmidtke, S.R., Will, T.J., Duchardt-Ferner, E., Hammann, C., Wöhnert, J. and Suess, B. (2011).
Mechanistic insights into an engineered riboswitch: A switching element which confers riboswitch activity.
 Nucleic Acids Research, 39, 3363-3372

Wiegand, S., Kruse, J., Gronemann, S. and Hammann, C. (2011).
Efficient generation of gene knockout plasmids for Dictyostelium discoideum using one-step cloning. 
Genomics 97, 321-325

Seehafer, C., Kalweit, A., Steger, G., Gräf, S. and Hammann, C. (2011)
From Alpaca to Zebrafish: hammerhead ribozymes wherever you look.
 RNA 17, 21-26



Hammann, C. and Westhof, E. (2009). The unforeseeable hammerhead ribozyme. F1000 Biology Reports 1, 8

Popov, C., Bliznakov, S., Boycheva, S., Milinovik, N., Apostolova, M.D., Anspach, N., Hammann, C., Nellen, W., Reithmaier, J.P. and Kulisch, W. (2008). Nanocrystalline diamond/amorphous carbon composite coatings for biomedical applications. Diamond and Related Materials 17, 882-887

Przybilski, R., Bajaj, P. and Hammann, C. (2007). Katalytische RNAs: Molekulare Fossilien der Evolution? Biologie in unserer Zeit 37, 356-364

Przybilski, R. and Hammann, C. (2007). The tolerance to exchanges of the Watson/Crick basepair in the hammerhead ribozyme core is determined by surrounding elements. RNA 13, 1625-1630

Hammann, C. and Westhof, E. (2007). Searching genomes for ribozymes and riboswitches. Genome Biology 8, 210

Przybilski, R. and Hammann, C. (2007). Idiosyncratic cleavage and ligation activity of individual hammerhead ribozymes and core sequence variants thereof. Biological Chemistry 388, 737-741

Hammann, C., Hartmann, R.K. and Marchfelder, A. (2007). 25 years of catalytic RNA: looking younger than ever! Biological Chemistry 388, 659-660

Moll, D., Schweinsberg, S., Hammann, C. and Herberg, F.W. (2007). Comparative thermodynamic analysis of cyclic nucleotide binding to protein kinase A. Biological Chemistry 388, 163-172

Popov, C., Kulisch, W., Reithmaier, J.P., Dostalova, T., Jelinek, M., Anspach, N. and Hammann, C. (2007). Bioproperties of nanocrystalline diamond/amorphous carbon composite films. Diamond and Related Materials 16, 735-739

Przybilski, R. and Hammann, C. (2006). The Hammerhead Ribozyme Structure Brought in Line. ChemBioChem 7, 1641-1644



Kuhlmann, M., Borisova, B.E., Kaller, M., Larsson, P., Stach, D., Na, J., Eichinger, L., Lyko, F., Ambros, V., Söderbom, F., Hammann, C. and Nellen, W. (2005). Silencing of retrotransposons in Dictyostelium by DNA methylation and RNAi. Nucleic Acids Research 33, 6405-6417

Gräf, S., Przybilski, R., Steger, G. and Hammann, C. (2005). A database search for hammerhead ribozyme motifs. Biochemical Society Transactions 33, 477-478

Przybilski, R., Gräf, S., Lescoute, A., Nellen, W., Westhof, E., Steger, G. and Hammann, C. (2005). Functional Hammerhead Ribozymes Naturally Encoded in the Genome of Arabidopsis thaliana. Plant Cell 17, 1877-1885

Gräf, S., Borisova, B.E., Nellen, W., Steger, G. and Hammann, C. (2004). A database search for double-strand containing RNAs in Dictyostelium discoideum. Biological Chemistry 385, 961-965

Hammann, C. (2003). RNA for everyone! ChemBioChem 4, 1103

Hammann, C. and Nellen, W. (2003). RNA: Two in one. Angewandte Chemie International Edition 42, 714

Hammann, C. and Lilley, D.M. (2002). Folding and activity of the hammerhead ribozyme. ChemBioChem 3, 690-700

Hammann, C. (2001). Die Faltung einer kleinen katalytischen RNA. BIOspektrum 6/01, 558

Hammann, C., Cooper, A. and Lilley, D.M.J. (2001). Thermodynamics of ion-induced RNA folding in the hammerhead ribozyme: an isothermal titration calorimetric study. Biochemistry 40, 1423-1429

Hammann, C., Norman, D.G. and Lilley, D.M. (2001). Dissection of the ion-induced folding of the hammerhead ribozyme using 19F NMR. Proceedings of the National Academy of Sciences USA 98, 5503-5508



Wittberger, D., Berens, C., Hammann, C., Westhof, E. and Schroeder, R. (2000). Evaluation of uranyl photocleavage as a probe to monitor ion binding and flexibility in RNAs. Journal of Molecular Biology 300, 339-352

Hammann, C. and Tabler, M. (1999). Quantitative recovery of nucleic acids from excised gel pieces by isotachophoresis. BioTechniques 26, 422-424

Hammann, C. and Tabler, M. (1999). Generation and application of asymmetric hammerhead ribozymes. Methods 18, 273-280

Hammann, C., Martinez, E., Moosbauer, J., Hormes, R. and Tabler, M. (1999). Length variation of helix III in a hammerhead ribozyme and its influence on cleavage activity. Antisense and Nucleic Acid Drug Development 9, 25-31

Hammann, C., Hormes, R., Sczakiel, G. and Tabler, M. (1997). A spermidine-induced conformational change of long-armed hammerhead ribozymes: ionic requirements for fast cleavage kinetics. Nucleic Acids Research 25, 4715-4722

Hammann, C., van Pouderoyen, G., Nar, H., Gomis-Rüth, F.-X., Messerschmidt, A., Huber, R., den Blaauwen, T. and Canters, G.W. (1997). Crystal structures of modified Apo-His117Gly and Apo-His46Gly mutants of Pseudomonas aeruginosa Azurin. Journal of Molecular Biology 266, 357-366

Hammann, C., Messerschmidt, A., Nar, H., Huber, R., Gilardi, G. and Canters, G.W. (1996). X-ray Crystal Structure of the Two Site-Specific Mutants Ile7Ser and Phe110Ser of Azurin from Pseudomonas aeruginosa. Journal of Molecular Biology 255, 362-366

Tsai, L., Sjölin, L., Langer, V., Bonander, N., Karlsson, B.G., Vänngård, T., Hammann, C. and Nar, H. (1995). Structure of the Azurin Mutant Nickel-Trp48Met from Pseudomonas aeruginosa at 2.2Å resolution. Acta Crystallographica D51, 711-717

Coremans, J.W., van Gastel, M., Poluektov, O.G., Groenen, E.J.J., den Blaauwen, T., van Pouderoyen, G., Canters, G.W., Nar, H., Hammann, C. and Messerschmidt, A. (1995). An ENDOR and ESEEM study of the blue copper protein Azurin. Chemical Physics Letters 235, 202-210


Book chapters

Klostermeier, D. and Hammann, C. (2013) Optical spectroscopy and calorimetry. In RNA Structure and Folding: Biophysical techniques and prediction methods, (eds. D. Klostermeier and C. Hammann), pp. 1-28, De Gruyter, Berlin/Boston.

Popova, B., Kulisch, W., Popov, C. and Hammann, C. (2006). Immobilization of RNA and protein biomolecules on nanocrystalline diamond for development of new biosensors. In Functional Properties of Nanostructured Materials, (eds. R. Kassing, P. Petkov, W. Kulisch and C. Popov), pp. 515-521. Springer Verlag, Berlin.

Hammann, C. (2005). Protein Interactions with Double Stranded RNA in Eukaryotic Cells. In Small RNAs: analysis and regulatory functions, Nucleic Acids and Molecular Biology Vol 17 (eds. W. Nellen and C. Hammann), pp. 91-118. Springer Verlag, Berlin.


Editor and Co-Editor

RNA Structure and Folding: Biophysical techniques and prediction methods. D. Klostermeier and C. Hammann, eds. (2013), De Gruyter, Berlin/Boston (ISBN 978-3-11-028459-1)

Small RNAs: Analysis and Regulatory Functions. Nellen, W. and Hammann, C., eds. (2005) Nucleic Acids and Molecular Biology, Vol. 17, Berlin, Springer Verlag (ISBN: 3-540-28129-0); appeared additionally in October 2007 as paperback issue (ISBN: 3-540-74270-8)

Epigenetics. Nellen, W., Hammann, C. and Kuhlmann, M., eds. (2003) Genes, Chromosomes, Genomes, Vol. 9 (ISBN 0944-6931)