Here we investigate one of these VP3 functions and present the crystal structure of the C-terminal 12 residues of VP3 bound to the VP1 polymerase. This interaction, visualized for the first time, reveals the precise molecular determinants used by VP3 to bind the polymerase. Competition binding studies confirm that this region of VP3 is necessary and sufficient for VP1 binding, while biochemical experiments show that VP3 attachment has no effect on polymerase activity. These results indicate how VP3 recruits the polymerase into birnavirus capsids during morphogenesis.”
“Calcium-binding protein 1 (CaBP1), a neuron-specific member of the calmodulin (CaM) superfamily, regulates the Ca2+-dependent

activity of inositol 1,4,5-triphosphate receptors (InsP3Rs) and various voltage-gated Ca2+ channels. Here, we present the NMR structure of full-length CaBP1 with

Ca2+ bound at the first, third, and fourth EF-hands. Lapatinib purchase A total of 1250 nuclear Overhauser effect distance measurements and 70 residual dipolar coupling restraints define the overall main chain structure with a root-mean-squared deviation of 0.54 angstrom (N-domain) and 0.48 angstrom (C-domain). The first 18 residues from the N-terminus in CaBP1 (located upstream of the first EF-hand) are structurally disordered and solvent exposed. The Ca2+-saturated CaBP1 structure contains two independent domains Selleck STI571 separated by a flexible central linker similar to that in calmodulin and troponin C. The N-domain structure of CaBP1 contains two EF-hands Maltase (EF1 and EF2), both in a closed conformation [interhelical angles = 129 degrees (EF1) and 142 degrees (EF2)]. The C-domain contains EF3 and EF4 in the familiar Ca2+-bound open conformation [interhelical angles = 105 degrees (EF3) and 91 degrees (EF4)]. Surprisingly, the N-domain adopts the same closed conformation in the presence or absence of Ca2+ bound at EF1. The Ca2+-bound closed

conformation of EF1 is reminiscent of Ca2+-bound EF-hands in a closed conformation found in cardiac troponin C and calpain. We propose that the Ca2+-bound closed conformation of EF1 in CaBP1 might undergo an induced-fit opening only in the presence of a specific target protein, and thus may help explain the highly specialized target binding by CaBP1.”
“The renewed interest in controlling Staphylococcus aureus infections using their natural enemies, bacteriophages, has led to the isolation of a limited number of virulent phages so far. These phages are all members of the Twortlikevirus, displaying little variance. We present two novel closely related (95.9% DNA homology) lytic myoviruses, Romulus and Remus, with double-stranded DNA (dsDNA) genomes of 131,333 bp and 134,643 bp, respectively. Despite their relatedness to Staphylococcus phages K, G1, ISP, and Twort and Listeria phages A511 and P100, Romulus and Remus can be proposed as isolates of a new species within the Twortlikevirus genus.