Regulation of stress granule maturation and dynamics by poly(ADP-ribose) interaction with PARP13.

Non-covalent interactions of poly(ADP-ribose) (PAR) facilitate condensate formation, yet the impact of these interactions on condensate properties remains unclear. Here, we demonstrate that PAR-mediated interactions through PARP13, specifically the PARP13.2 isoform, are essential for modulating the dynamics of stress granules-a class of cytoplasmic condensates that form upon stress, including types frequently observed in cancers.

Crystal structures and functional analysis of the ZnF5-WWE1-WWE2 region of PARP13/ZAP define a distinctive mode of engaging poly(ADP-ribose).

PARP13/ZAP (zinc-finger antiviral protein) acts against multiple viruses by promoting degradation of viral mRNA. PARP13 has four N-terminal zinc (Zn) fingers that bind CG-rich nucleotide sequences, a C-terminal ADP ribosyltransferase fold, and a central region with a fifth Zn finger and tandem WWE domains. The central PARP13 region, ZnF5-WWE1-WWE2, is implicated in binding poly(ADP-ribose); however, there are limited insights into its structure and function.

Structure and function of the putative thioredoxin 1 from the thermophilic eubacterium Thermosipho africanus strain TCF52B.

The thioredoxin system is a ubiquitous oxidoreductase system that consists of the enzyme thioredoxin reductase (TrxR), its cofactor nicotinamide adenine dinucleotide phosphate (NAD(P)H) and the protein thioredoxin (Trx). The system has been comprehensively studied from many organisms, such as Escherichia coli (E. coli); however, structural and functional analysis of this system from thermophilic bacteria has not been as extensive.

Analysis of plant UDP-arabinopyranose mutase (UAM): Role of divalent metals and structure prediction.

UDP-arabinopyranose mutase (UAM) is a plant enzyme which interconverts UDP-arabinopyranose (UDP-Arap; a six-membered sugar) to UDP-arabinofuranose (UDP-Araf; a five-membered sugar). Plant mutases belong to a small gene family called Reversibly Glycosylated Proteins (RGPs). So far, UAM has been identified in Oryza sativa (Rice), Arabidopsis thaliana and Hordeum vulgare (Barley).

A Second, Druggable Binding Site in UDP-Galactopyranose Mutase from Mycobacterium tuberculosis?

UDP-galactopyranose mutase (UGM), a key enzyme in the biosynthesis of mycobacterial cell walls, is a potential target for the treatment of tuberculosis. In this work, we investigate binding models of a non-substrate-like inhibitor, MS-208, with M. tuberculosis UGM.

Putative thioredoxin Trx1 from Thermosipho africanus strain TCF52B: expression, purification and structural determination using S-SAD.

Thioredoxin is a small ubiquitous protein that plays a role in many biological processes. A putative thioredoxin, Trx1, from Thermosipho africanus strain TCF52B, which has low sequence identity to its closest homologues, was successfully cloned, overexpressed and purified. The protein was crystallized using the microbatch-under-oil technique at 289 K in a variety of conditions; crystals grown in 0.

Structural basis of ligand binding to UDP-galactopyranose mutase from Mycobacterium tuberculosis using substrate and tetrafluorinated substrate analogues.

UDP-Galactopyranose mutase (UGM) is a flavin-containing enzyme that catalyzes the reversible conversion of UDP-galactopyranose (UDP-Galp) to UDP-galactofuranose (UDP-Galf) and plays a key role in the biosynthesis of the mycobacterial cell wall galactofuran. A soluble, active form of UGM from Mycobacterium tuberculosis (MtUGM) was obtained from a dual His6-MBP-tagged MtUGM construct. We present the first complex structures of MtUGM with bound substrate UDP-Galp (both oxidized flavin and reduced flavin).