Roman Peter Jakob

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TamA is an Escherichia coli Omp85 protein involved in autotransporter biogenesis. It comprises a 16-stranded transmembrane β-barrel and three POTRA domains. The 2.3-Å crystal structure reveals that the TamA barrel is closed at the extracellular face by a conserved lid loop. The C-terminal β-strand of the barrel forms an unusual inward kink, which weakens(More)
In vitro selections of stabilized proteins lead to more robust enzymes and, at the same time, yield novel insights into the principles of protein stability. We employed Proside, a method of in vitro selection, to find stabilized variants of TEM-1 beta-lactamase from Escherichia coli. Proside links the increased protease resistance of stabilized proteins to(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)
Urinary tract infections caused by uropathogenic E. coli are among the most prevalent infectious diseases. The mannose-specific lectin FimH mediates the adhesion of the bacteria to the urothelium, thus enabling host cell invasion and recurrent infections. An attractive alternative to antibiotic treatment is the development of FimH antagonists that mimic the(More)
Quercetinase (QueD) of Streptomyces sp. FLA is an enzyme of the monocupin family and catalyzes the 2,4-dioxygenolytic cleavage of the flavonol quercetin. After expression of the queD gene in Escherichia coli, high specific QueD activity was found in crude cell extracts when the growth medium was supplemented with NiCl 2 or CoCl 2, but not when Mn (2+), Fe(More)
In folded proteins, prolyl peptide bonds are usually thought to be either trans or cis because only one of the isomers can be accommodated in the native folded protein. For the N-terminal domain of the gene-3 protein of the filamentous phage fd (N2 domain), Pro161 resides at the tip of a beta hairpin and was found to be cis in the crystal structure of this(More)
Polyketide synthases (PKSs) are biosynthetic factories that produce natural products with important biological and pharmacological activities. Their exceptional product diversity is encoded in a modular architecture. Modular PKSs (modPKSs) catalyse reactions colinear to the order of modules in an assembly line, whereas iterative PKSs (iPKSs) use a single(More)
The cis/trans isomerization of peptide bonds before proline (prolyl bonds) is a rate-limiting step in many protein folding reactions, and it is used to switch between alternate functional states of folded proteins. Several prolyl isomerases of the FK506-binding protein family, such as trigger factor, SlyD, and FkpA, contain chaperone domains and are assumed(More)
Ligand-receptor interactions that are reinforced by mechanical stress, so-called catch-bonds, play a major role in cell-cell adhesion. They critically contribute to widespread urinary tract infections by pathogenic Escherichia coli strains. These pathogens attach to host epithelia via the adhesin FimH, a two-domain protein at the tip of type I pili(More)
E-selectin is a cell-adhesion molecule of the vascular endothelium that promotes essential leukocyte rolling in the early inflammatory response by binding to glycoproteins containing the tetrasaccharide sialyl Lewis(x) (sLe(x)). Efficient leukocyte recruitment under vascular flow conditions depends on an increased lifetime of E-selectin/ligand complexes(More)