Evaluation of the Kinetic Properties of the Sporulation Protein SpoIIE of Bacillus subtilis by Inclusion in a Model Membrane

Starvation induces Bacillus subtilis to initiate a developmental process (sporulation) that includes asymmetric cell division to form the prespore and the mother cell. The integral membrane protein SpoIIE is essential for the prespore-specific activation of the transcription factor σ(F), and it also has a morphogenic activity required for asymmetric division. An increase in the local concentration of SpoIIE at the polar septum of B. subtilis precedes dephosphorylation of the anti-anti-sigma factor SpoIIAA in the prespore. After closure and invagination of the asymmetric septum, phosphatase activity of SpoIIE increases severalfold, but the reason for this dramatic change in activity has not been determined. The central domain of SpoIIE has been seen to self-associate (I. Lucet et al., EMBO J. 19:1467-1475, 2000), suggesting that activation of the C-terminal PP2C-like phosphatase domain might be due to conformational changes brought about by the increased local concentration of SpoIIE in the sporulating septum. Here we report the inclusion of purified SpoIIE protein into a model membrane as a method for studying the effect of local concentration in a lipid bilayer on activity. In vitro assays indicate that the membrane-bound enzyme maintains dephosphorylation rates similar to the highly active micellar state at all molar ratios of protein to lipid. Atomic force microscopy images indicate that increased local concentration does not lead to self-association

CAGI, the Critical Assessment of Genome Interpretation, establishes progress and prospects for computational genetic variant interpretation methods

Background: The Critical Assessment of Genome Interpretation (CAGI) aims to advance the state-of-the-art for computational prediction of genetic variant impact, particularly where relevant to disease. The five complete editions of the CAGI community experiment comprised 50 challenges, in which participants made blind predictions of phenotypes from genetic data, and these were evaluated by independent assessors. // Results: Performance was particularly strong for clinical pathogenic variants, including some difficult-to-diagnose cases, and extends to interpretation of cancer-related variants. Missense variant interpretation methods were able to estimate biochemical effects with increasing accuracy. Assessment of methods for regulatory variants and complex trait disease risk was less definitive and indicates performance potentially suitable for auxiliary use in the clinic. // Conclusions: Results show that while current methods are imperfect, they have major utility for research and clinical applications. Emerging methods and increasingly large, robust datasets for training and assessment promise further progress ahead

Anomalous Migration of Short Sequences of Nucleic Acids in Polyacrylamide Gels: Prediction and Experiment

Anomalous Migration of Short Sequences of Nucleic Acids in Polyacrylamide Gels:  Prediction and Experimen

Anomalous Migration of Short Sequences of Nucleic Acids in Polyacrylamide Gels: Prediction and Experiment

Anomalous Migration of Short Sequences of Nucleic Acids in Polyacrylamide Gels:  Prediction and Experimen