The adeno-associated virus (AAV) non-structural Rep proteins catalyze all the DNA transactions required for virus viability including, DNA replication, transcription regulation, genome packaging, and during the latent phase, site-specific integration. Rep proteins contain two multifunctional domains: an Origin Binding Domain (OBD) and a SF3 helicase domain (HD). Studies have shown that Rep proteins have a dynamic oligomeric behavior where the nature of the DNA substrate molecule modulates its oligomeric state. In the presence of ssDNA, Rep68 forms a large double-octameric ring complex. To understand the mechanisms underlying AAV Rep function, we investigated the cryo-EM and X-ray structures of Rep68-ssDNA complexes. Surprisingly, Rep68 generates hybrid ring structures where the OBD forms octameric rings while the HD forms heptamers. Moreover, the binding to ATPγS promotes a large conformational change in the entire AAA+ domain that leads the HD to form both heptamer and hexamers. The HD oligomerization is driven by an interdomain linker region that acts as a latch to 'catch' the neighboring HD subunit and is flexible enough to permit the formation of different stoichiometric ring structures. Overall, our studies show the structural basis of AAV Rep's structural flexibility required to fulfill its multifunctional role during the AAV life cycle.
Background: NeoDura (Medprin Biotech Gmbh) is an absorbable dural repair patch consisting of degradable poly-L-lactic acid and porcine gelatin that provides a hermetic closure of the dura mater (Medprin Biotech. Neodura. Dural Repair Patch [Brochure].
The bioluminescence reaction of firefly luciferase with D-luciferin has become an indispensable imaging technique in modern biology and life science experiments, but the high cost of D-luciferin is limiting its further application. Here, we report a practical, one-pot synthesis of D-luciferin from p-benzoquinone (p-BQ), L-cysteine methyl ester and D-cysteine, with an overall yield of 46%. Our route, which is six steps in length and proceeds via 2-cyano-6-hydroxybenzothiazole, is inspired by the mechanistic study of our previously reported biomimetic, non-enzymatic, one-pot formation of L-luciferin from p-BQ and L-cysteine.
Background: Thrombotic microangiopathy (TMA) is a rare, life-threatening disorder characterized by microangiopathic hemolytic anemia, thrombocytopenia, and end-organ damage. Atypical hemolytic uremic syndrome (aHUS) is even less common, comprising less than 10% of hemolytic uremic syndrome (HUS) cases. aHUS in postpartum is associated with poor maternal outcomes, with the majority of cases resulting in end-stage renal disease.
National Key Laboratory of Cotton Bio-breeding and Integrated Utilization, School of Life Science, Henan University, Kaifeng, Henan 475004, P.R. China. Electronic address:
Gossypium spp. pigment glands are a good model for studying plant secretory cavity structures. GoPGF (GOSSYPIUM PIGMENT GLAND FORMATION) is a well-characterized master transcription factor that controls gland formation in cotton; however, little is known about its transcriptional regulation.
Previously, it was reported that mRNA/cationic liposome complexes (mRNA lipoplexes) composed of the cationic triacyl lipid, 11-((1,3-bis(dodecanoyloxy)-2-((dodecanoyloxy)methyl)propan-2-yl)amino)-,,- trimethyl-11-oxoundecan-1-aminium bromide (TC-1-12), with 1,2-dioleoyl-glycero-3-phosphoethanolamine and poly(ethylene glycol) cholesteryl ether, induce high protein expression in human cervical carcinoma HeLa cells. In the present study, the authors aimed to optimize mRNA transfection using TC-1-12-based mRNA lipoplexes. mRNA lipoplexes were prepared at various charge ratios (+:-) using modified ethanol injection (MEI) and thin-film hydration (TFH) methods and compared the protein expression efficiency after transfection of HeLa cells with the developed mRNA lipoplexes.
