Genetic evidence of two stocks of the whitemouth croaker Micropogonias furnieri in the Río de la Plata and oceanic front in Uruguay

Analysis of the mitochondrial DNA control region resolved two stocks of whitemouth croaker Micropogonias furnieri in Uruguayan waters, one in the Río de la Plata and the other on the Uruguayan shelf. The whitemouth croaker is the most important coastal fishery resource along the coast and has the greatest commercial importance in the Río de la Plata and its oceanic front. The number of pair-wise differences (π) and haplotype diversity ( h ) showed significant differences between the two regions. Frequencies of mtDNA haplotypes did not differ between Río de la Plata from Bahia Blanca M. furnieri . Samples from the oceanic front showed greater genetic variability and a larger effective number of females that were an order of magnitude larger than that in Río de la Plata. Mismatch distributions showed evidence of a recent population expansion in the oceanic region, beginning c. 40 000 b.p. The presence of two stocks of the M. furnieri in the study area should be considered in the management of this species' fishery.     

Crystal Structure of the Engineered Neutralizing Antibody M18 Complexed to Domain 4 of the Anthrax Protective Antigen

The virulence of Bacillus anthracis is critically dependent on the cytotoxic components of the anthrax toxin, lethal factor (LF) and edema factor (EF). LF and EF gain entry into host cells through interactions with the protective antigen (PA), which binds to host cellular receptors such as CMG2. Antibodies that neutralize PA have been shown to confer protection in animal models and are undergoing intense clinical development. A murine monoclonal antibody, 14B7, has been reported to interact with domain 4 of PA (PAD4) and block its binding to CMG2. More recently, the 14B7 antibody was used as the platform for the selection of very high affinity, single-chain antibodies that have tremendous potential as a combination anthrax prophylactic and treatment. Here, we report the high-resolution X-ray structures of three high-affinity, single-chain antibodies in the 14B7 family; 14B7 and two high-affinity variants 1H and M18. In addition, we present the first neutralizing antibody-PA structure, M18 in complex with PAD4 at 3.8 Å resolution. These structures provide insights into the mechanism of neutralization, and the effect of various mutations on antibody affinity, and enable a comparison between the binding of the M18 antibody and CMG2 with PAD4.     

Interaction in vivo between the Two Matrix Attachment Regions Flanking a Single Chromatin Loop

In interphase nuclei as in metaphase chromosomes, the genome is organized into topologically closed loop domains. Here, we have mapped the ends of the loop domain that contains the Ifng (interferon-γ) gene in primary and cultured murine T-lymphocytes. To determine whether the ends of the loop are located in close proximity to each other in the nuclear space, the 3C (chromosome conformation capture) technique, which detects protein-mediated DNA-DNA interactions, was utilized. A strong interaction was demonstrated between the two ends of the loop, which were close enough to become cross-linked in vivo in the presence of paraformaldehyde. Chromatin immunoprecipitation combined with the 3C technique demonstrated that topoisomerase IIα and MeCP2, but not topoisomerase IIβ, heterochromatin-associated protein HP1 or CTCF, were involved in this interaction. The present findings have important implications in terms of mechanisms of illegitimate recombination that can result in chromosomal translocations and deletions.     

Association of the eukaryotic V1VO ATPase subunits a with d and d with A

Owing to the complex nature of V₁V_O ATPases, identification of neighboring subunits is essential for mechanistic understanding of this enzyme. Here, we describe the links between the V₁ headpiece and the V_O-domain of the yeast V₁V_O ATPase via subunit A and d as well as the V_O subunits a and d using surface plasmon resonance and fluorescence correlation spectroscopy. Binding constants of about 60 and 200 nM have been determined for the a-d and d-A assembly, respectively. The data are discussed in light of subunit a and d forming a peripheral stalk, connecting the catalytic A₃B₃ hexamer with V_O.

Structured summary

MINT-7012054: d (uniprotkb:P32366) binds (MI:0407) to A (uniprotkb:P17255) by fluorescence correlation spectroscopy (MI:0052)MINT-7012041: d (uniprotkb:P32366) binds (MI:0407) to A (uniprotkb:P17255) by surface plasmon resonance (MI:0107)MINT-7012028: d (uniprotkb:P32366) binds (MI:0407) to a (uniprotkb:P32563) by surface plasmon resonance (MI:0107)     

Hepatitis C virus NS5A protein modulates template selection by the RNA polymerase in in vitro system

Hepatitis C virus (HCV) NS5A phosphoprotein is a component of virus replicase. Here we demonstrate that in vitro unphosphorylated NS5A protein inhibits HCV RNA-dependent RNA polymerase (RdRp) activity in polyA-oligoU system but has little effect on synthesis of viral RNA. The phosphorylated casein kinase (CK) II NS5A protein causes the opposite effect on RdRp in each of these systems. The phosphorylation of NS5A protein with CKII does not affect its affinity to the HCV RdRp and RNA. The NS5A phosphorylation with CKI does not change the RdRp activity. Herein we report evidence that the NS5A prevents template binding to the RdRp.

Structured summary

MINT-6803697: CKI (uniprotkb:P97633) phosphorylates (MI:0217) NS5A (uniprotkb:P26662) by protein kinase assay (MI:0424)MINT-6803713: CKII (uniprotkb:P67870) phosphorylates (MI:0217) NS5A (uniprotkb:P26662) by protein kinase assay (MI:0424)     

CDF it all: Consensus prediction of intrinsically disordered proteins based on various cumulative distribution functions

Many biologically active proteins are intrinsically disordered. A reasonable understanding of the disorder status of these proteins may be beneficial for better understanding of their structures and functions. The disorder contents of disordered proteins vary dramatically, with two extremes being fully ordered and fully disordered proteins. Often, it is necessary to perform a binary classification and classify a whole protein as ordered or disordered. Here, an improved error estimation technique was applied to develop the cumulative distribution function (CDF) algorithms for several established disorder predictors. A consensus binary predictor, based on the artificial neural networks, NN-CDF, was developed by using output of the individual CDFs. The consensus method outperforms the individual predictors by 4-5% in the averaged accuracy.