Self-contacting Cys, Ser, and Thr residues in high-resolution protein crystal structures: Tertiary constraints or hydrogen bonds?

Functional groups in the side-chains of at least 10 amino acids are mainly involved in tertiary interactions. However, structural and functional significance of intra-residue interactions has not been fully recognized. In this study, we have analyzed ~5800 non-redundant high-resolution protein structures and identified 1166 self-contacts between the side-chain S-H/O-H and backbone C=O groups in Cys, Ser, and Thr residues that satisfied the geometric criteria to form hydrogen bonds.

Differences in the Membrane-Binding Properties of Flaviviral Nonstructural 1 (NS1) Protein: Comparative Simulations of Zika and Dengue Virus NS1 Proteins in Explicit Bilayers.

NS1 in flaviviruses is the only nonstructural protein that is secretory and interacts with different cellular components of the host cell membrane. NS1 is localized in the ER as a dimer to facilitate viral replication. Crystal structures of NS1 homologues from zika (ZIKV) and dengue (DENV) viruses have revealed the organization of different domains in NS1 dimers.

Crystal Engineering and Self-Assembled Nanoring Formation with Purine-Cd/Hg Supramolecular Frameworks.

We report three complexes of Cd and Hg with two purine rare tautomers, N9-(pyridin-2-ylmethyl)-N-methoxyadenine, L1 and N7-(pyridin-2-ylmethyl)-N-methoxyadenine, L2, highlighting diverse crystallographic signatures exhibited by them. Influence of substituents, binding sites, steric effects and metal salts on the different modes of binding enabled an insight into metal-nucleobase interactions. L1 interacted with two and three equivalents of Cd(NO).

Substrate selectivity and unique sequence signatures in SWEET/semiSWEET homologs of four taxonomic groups: Sequence analysis and phylogenetic studies.

The recently discovered SWEET (Sugar Will Eventually be Exported Transporter) proteins are involved in the selective transport of monosaccharides and disaccharides. The prokaryotic counterparts, semiSWEETs, form dimers with each monomer forming a triple-helix transmembrane bundle (THB). The longer eukaryotic SWEETs have seven transmembrane helices with two THBs and a linker helix.

dbAQP-SNP: a database of missense single-nucleotide polymorphisms in human aquaporins.

Aquaporins and aquaglyceroporins belong to the superfamily of major intrinsic proteins (MIPs), and they transport water and other neutral solutes such as glycerol. These channel proteins are involved in vital physiological processes and are implicated in several human diseases. Experimentally determined structures of MIPs from diverse organisms reveal a unique hour-glass fold with six transmembrane helices and two half-helices.