crystal structure analysis; pathogenic bacteria; signaling; second messenger; molecular mechanism; novel targets for antibiotics
Reinders Alberto, Hee Chee-Seng, Ozaki Shogo, Mazur Adam, Boehm Alex, Schirmer Tilman, Jenal Urs (2016), Expression and Genetic Activation of Cyclic Di-GMP-Specific Phosphodiesterases in Escherichia coli, in Journal of Bacteriology
, 198(3), 448-462.
Stanger Frédéric V, Burmann Björn M, Harms Alexander, Aragão Hugo, Mazur Adam, Sharpe Timothy, Dehio Christoph, Hiller Sebastian, Schirmer Tilman (2016), Intrinsic regulation of FIC-domain AMP-transferases by oligomerization and automodification., in Proceedings of the National Academy of Sciences of the United States of America
, 113(5), 529-37.
Harms Alexander, Stanger Frédéric Valentin, Scheu Patrick Daniel, de Jong Imke Greet, Goepfert Arnaud, Glatter Timo, Gerdes Kenn, Schirmer Tilman, Dehio Christoph (2015), Adenylylation of Gyrase and Topo IV by FicT Toxins Disrupts Bacterial DNA Topology., in Cell reports
, 12(9), 1497-507.
Ozaki Shogo, Schalch-Moser Annina, Zumthor Ludwig, Manfredi Pablo, Ebbensgaard Anna, Schirmer Tilman, Jenal Urs (2014), Activation and polar sequestration of PopA, a c-di-GMP effector protein involved in Caulobacter crescentus cell cycle control., in Molecular microbiology
, 94(3), 580-94.
Sundriyal Amit, Massa Claudia, Samoray Dietrich, Zehender Fabian, Sharpe Timothy, Jenal Urs, Schirmer Tilman (2014), Inherent regulation of EAL domain-catalyzed hydrolysis of second messenger cyclic di-GMP., in The Journal of biological chemistry
, 289(10), 6978-90.
Goepfert Arnaud, Stanger Frédéric V, Dehio Christoph, Schirmer Tilman (2013), Conserved inhibitory mechanism and competent ATP binding mode for adenylyltransferases with Fic fold., in PloS one
, 8(5), 64901-64901.
Zähringer Franziska, Lacanna Egidio, Jenal Urs, Schirmer Tilman, Boehm Alex (2013), Structure and signaling mechanism of a zinc-sensory diguanylate cyclase., in Structure (London, England : 1993)
, 21(7), 1149-57.
Goepfert Arnaud, Harms Alexander, Schirmer Tilman, Dehio Christoph (2013), Type II toxin - antitoxin loci: the fic family., in Gerdes Ken (ed.), Springer, Berlin, Heidelberg, 177-187.
Our general aim is to contribute to the understanding, on the molecular level, of the mechanisms by which proteins perform their action. For this we are combining X-ray structure analysis, functional and biophysical characterization, and site-directed mutagenesis. Here, we propose research on components of the bacterial c-di-GMP signaling pathway, which we are studying for several years, and on adenylyl transferases with a Fic domain.(A) Via the second messenger cyclic di-GMP, a large variety of cell surface associated traits are regulated in response to internal and external stimuli. We aim to unravel the mechanisms through which c-di-GMP specific phosphodiesterases are regulated by their associated regulatory domains, such as Rec, PAS, and DNA binding domains. A working hypothesis has previously been derived from our study on the YkuI protein that predicts coupling of quarternary state and active site geometry of the phoshodiesterase. Furthermore, we want to determine the structures of novel c-di-GMP binding proteins (effector proteins) that are putatively involved in the control of transcription and in the synthesis and export of capsular polysaccharide. This will provide insight into mechanisms of down-stream signaling. (B) AMPylation, i.e. transfer of a AMP moiety, is a recently discovered strategy of bacteria to subvert host cell function. This process is catalyzed by the Fic domain and we propose to continue our studies on the molecular mechanism of this activity. Most recently it has been discovered that effector proteins of the type 4 secretion system (T4SS) with a Fic domain are inhibited by cognate antitoxins, probably to avoid AMPylation of endogenous proteins. We have started to elucidate the molecular basis of this interaction and want to unravel the inhibitory mechanism. Furthermore, we want to extend our studies to stand-alone Fic proteins from E. coli and N. meningitis that probably AMPylate endogenous targets. Interestingly, some of these proteins appear to utilize a related, but autoinhibitory, mechanism. Identification of Fic targets and structure determination Fic/target structures will follow to reveal structural determinants of target affinity and specificity.