coli at a very low external substrate concentration, the Tsx channel is likely to contain a binding site for this antibiotic. To identify residues involved in the Tsx substrate-specific channel activity, we devised a selection scheme to isolate albicidin-resistant tsx mutants synthesizing Tsx ...
These proteins are thought to function as a scaffold (ExbB)16,17 and to harness the proton motive force (ExbD)18, a pre-requisite for TonB-dependent activity. While it is known that TonB-mediated transport requires TonB to be tethered to an energized IM19, the mechanism by which TonB ...
et al. A novel miRNA processing pathway independent of Dicer requires Argonaute2 catalytic activity. Science 328, 1694–1698 (2010). Article CAS Google Scholar Cheloufi, S., Dos Santos, C.O., Chong, M.M. & Hannon, G.J.A. Dicer-independent miRNA biogenesis pathway that requires Ago ...
High-molecular-weight (Ub)n-GFPu∗ conjugates were rescued by re-expressing wild-type UBE3C, but not UBE3CC1051A, in UBE3CKO cells, confirming that catalytic activity of this E3 is essential for chain extension on oligoubiquitylated GFPu∗ (Figure 2G). In addition to catalyzing K48-...
As a consequence, it accumulated FeMo-co-deficient apo-NifDK and was impaired in NifDK activity. We conclude that FdxN plays a role in FeMo-co biosynthesis, presumably by donating electrons to support NifB-co synthesis by NifB. This is the first role in nitrogenase biosynthesis unequivocally...
ALDH1A3 also demonstrated esterase activity for PNP-acetate, alike to ALDHTt. Across ALDHs, substrate specificity has been related to the shape and geometry of the substrate entry channel of the enzyme, linked to three key amino acids at distinct positions, termed the “mouth” (136), “...
Alteration of residues located at the cytoplasmic or the inner membrane interface resulted in lower activity in vivo and in vitro, while variants affecting residues in the central region of the channel showed increased DNA and protein transfer efficiency and higher ATPase activity, especially in the ...
The exoglycohydrolase activity of ARH3 cleaves the α(1″-2′) O-glycosidic bond between n and n − 1 ADP-ribose, releasing ADP-ribose as a product. b, left, Mg2+ enhances the ADP-ribosyl-acceptor hydrolase activity of ARH3. The ARH3-mediated hydrolysis of PAR on PARylated PARP1C...
Widely known for its vasoprotective activity, PGI2 is mainly synthesized in the endothelial and smooth muscle cells via an isomerization of prostaglandin H2 (Fig. 1A), a reaction catalyzed by prostacyclin synthase (PGI2 synthase; PGIS). PGIS is localized to the endoplasmic reticulum membrane and ...