Michael Kovermann

Learn More
PpiD is a periplasmic folding helper protein of Escherichia coli. It consists of an N-terminal helix that anchors PpiD in the inner membrane near the SecYEG translocon, followed by three periplasmic domains. The second domain (residues 264-357) shows homology to parvulin-like prolyl isomerases. This domain is a well folded, stable protein and follows a(More)
Enzymes have evolved with highly specific values of their catalytic parameters kcat and KM. This poses fundamental biological questions about the selection pressures responsible for evolutionary tuning of these parameters. Here we are address these questions for the enzyme adenylate kinase (Adk) in eukaryotic yeast cells. A plasmid shuffling system was(More)
The Escherichia coli peptide binding protein OppA is an essential component of the oligopeptide transporter Opp. Based on studies on its orthologue from Salmonella typhimurium, it has been proposed that OppA binds peptides between two and five amino acids long, with no apparent sequence selectivity. Here, we studied peptide binding to E. coli OppA directly(More)
Uptake of copper (Cu) ions into human cells is mediated by the plasma membrane protein Ctr1 and is followed by Cu transfer to cytoplasmic Cu chaperones for delivery to Cu-dependent enzymes. The C-terminal cytoplasmic tail of Ctr1 is a 13-residue peptide harboring an HCH motif that is thought to interact with Cu. We here employ biophysical experiments under(More)
The hepatitis C virus (HCV) RNA-dependent RNA polymerase NS5B is a central enzyme of the intracellular replication of the viral (+)RNA genome. Here, we studied the individual steps of NS5B-catalyzed RNA synthesis by a combination of biophysical methods, including real-time 1D (1)H NMR spectroscopy. NS5B was found to bind to a nonstructured and a structured(More)
D-Alanylation of lipoteichoic acids plays an important role in modulating the properties of Gram-positive bacteria cell walls. The D-alanyl carrier protein DltC from Bacillus subtilis has been solved in apo- and two cofactor-modified holo-forms, whereby the entire phosphopantetheine moiety is defined in one. The atomic resolution of the apo-structure allows(More)
Polar lipid pattern determination is often used for the taxonomic classification of halophilic Archaea in addition to a genomic characterization. During the analysis of polar lipid extracts from the recently described haloarchaeon Natrononomonas moolapensis, an unknown glycolipid was detected. Fragmentation patterns observed from preliminary mass(More)
After Ctr1-mediated copper ion (Cu) entry into the human cytoplasm, chaperones Atox1 and CCS deliver Cu to P1B-type ATPases and to superoxide dismutase, respectively, via direct protein–protein interactions. Although the two Cu chaperones are presumed to work along independent pathways, we here assessed cross-reactivity between Atox1 and the first domain of(More)
The dynamics of the two domain prolyl-peptidyl cis/trans isomerase and chaperone SlyD was studied on a ps-to-ns time scale to correlate dynamic changes with the catalytic function. (15)N transversal and longitudinal relaxation rates as well as heteronuclear Overhauser effects were determined at different temperatures for Escherichia coli SlyD (EcSlyD) and(More)
It is widely known that the ability of sugar glasses to preserve anhydrobiotic systems in nature is important but the process is not yet fully understood. Molecular motions in the glassy state are likely to be important in the process but until now have remained largely uncharacterized. Here we describe the use of 1D 13C NMR exchange experiments using CODEX(More)