The endogenous ligand of guanylyl cyclase C, guanylin, is produced as the 94-amino-acid prohormone proguanylin, with the hormone guanylin located at the COOH terminus of the prohormone. The solution structure of proguanylin adopts a new protein fold and consists of a three-helix bundle, a small three-stranded beta-sheet of two NH2-terminal strands and one COOH-terminal strand, and an unstructur...

The structurally unique amino-terminal domain of class II G protein-coupled receptors is critically important for ligand binding and receptor activation. Understanding the precise role it plays requires detailed insights into the molecular basis of its ligand interactions and the conformation of the ligand-receptor complex. In this work, we used two high-affinity, full-agonist, secretin-like ph...

In the title complex, [Cr(C(4)H(6))(CO)(4)], the Cr(0) atom shows a distorted octa-hedral environment from four C atoms of the carbonyl ligands and the two π-bonds of the s-cis-1,3-butadiene ligand. The complex has an approximate non-crystallographic mirror symmetry m passing through the chromium atom, two carbonyl ligands and the mid-point of the central C-C bond of the s-cis-1,3-butadiene lig...

Serine dehydrogenase from Escherichia coli is a homotetrameric enzyme belonging to the short-chain dehydrogenase/reductase (SDR) family. This enzyme catalyses the NADP(+)-dependent oxidation of serine to 2-aminomalonate semialdehyde. The enzyme shows a stereospecificity for β-(3S)-hydroxy acid as a substrate; however, no stereospecificity was observed at the α-carbon. The structures of the liga...

The N-terminal extracellular parts of human G-protein coupled receptor class B, for example, receptors for secretin, glucagon, or parathyroid hormone, are involved in ligand binding. To obtain structural and functional information on the N-terminal receptor fragment of human parathyroid hormone receptor 1 (PTHR1), the truncated receptor was expressed in the cytosol of Escherichia coli in the fo...

Most peptide ligands presented by MHC class I molecules are the product of an intracellular pathway comprising protein breakdown in the cytosol, transport into the endoplasmic reticulum, and successive N-terminal trimming events. The efficiency of each of these processes depends on the amino acid sequence of the presented ligand and its precursors. Thus, relating the amino acid composition N-te...

Cancer-associated human papillomaviruses (HPVs) express E6 oncoproteins that target the degradation of p53 and have a carboxy-terminal PDZ ligand that is required for stable episomal maintenance of the HPV genome. We find that the E6 PDZ ligand can be deleted and the HPV genome stably maintained if cellular p53 is inactivated. This indicates that the E6-PDZ interaction promotes HPV genome maint...

In the title triangulo-triruthenium compound, [Ru(3)(C(6)H(12)Cl(3)O(3)P)(CO)(11)], one equatorial carbonyl ligand is substituted by a monodentate phosphite ligand, leaving one equatorial and two axial carbonyl ligands on one Ru atom. The remaining two Ru atoms each carry two equatorial and two axial terminal carbonyl ligands. In the crystal structure, the mol-ecules are linked into a one-dimen...

An unprecedented trinuclear heteroleptic Ag(I) complex was isolated using a stable multidentate 2,4,6-tris(2-pyrimidyl)-1,3,5-triazine (TPymT) ligand. The obtained compound is an efficient catalyst for the direct aziridination of terminal olefins.

Palladium on charcoal serves as an efficient and reusable solid supported catalyst for the Sonogashira coupling of aryl chlorides with terminal acetylenes in the presence of a bulky, electron-rich biphenyl type ligand (XPhos), without copper co-catalyst.