Advantages of combined transmembrane topology and signal peptide prediction - the Phobius web server
NUCLEIC ACIDS RESEARCH
Authors: Kaell, Lukas; Krogh, Anders; Sonnhammer, Erik L. L.
Abstract
When using conventional transmembrane topology and signal peptide predictors, such as TMHMM and SignalP, there is a substantial overlap between these two types of predictions. Applying these methods to five complete proteomes, we found that 30-65% of all predicted signal peptides and 25-35% of all predicted transmembrane topologies overlap. This impairs predictions of 5-10% of the proteome, hence this is an important issue in protein annotation. To address this problem, we previously designed a hidden Markov model, Phobius, that combines transmembrane topology and signal peptide predictions. The method makes an optimal choice between transmembrane segments and signal peptides, and also allows constrained and homology-enriched predictions. We here present a web interface (http://phobius.cgb.ki.se and http://phobius.binf.ku.dk) to access Phobius.
SHRIMP zircon and titanite U-Pb ages, Lu-Hf isotope signatures and geochemical constraints for similar to 2.56 Ga granitic magmatism in Western Dharwar Craton, Southern India: Evidence for short-lived Neoarchean episodic crustal growth?
PRECAMBRIAN RESEARCH
Authors: Mohan, M. Ram; Sarma, D. Srinivasa; McNaughton, Neal J.; Fletcher, Ian R.; Wilde, Simon A.; Siddiqui, Md. Alam; Rasmussen, Birger; Krapez, Bryan; Gregory, Courtney J.; Kamo, Sandra L.
Abstract
SHRIMP U-Pb zircon and titanite age data for granites adjacent to the Gadag greenstone belt (GGB) in the Western Dharwar Craton (WDC), India, establish the occurrence of voluminous similar to 2.56 Ga granitic magmatism and indicate the development and evolution of the GGB over a time span of similar to 70 m.y. These new data show that the GGB has an evolutionary history distinct from the Chitradurga greenstone belt (CGB) to the south, which was previously considered to be linked to that of the GGB, based on the continuity of lithological associations. Whole rock geochemical data indicate granites marginal to the GGB are potassic, were derived from intracrustal melting of an arc crust, without the involvement of mantle, and demonstrates the prevalence of horizontal tectonics in the evolution of Dharwar Craton. Lu-Hf zircon studies indicate that these rocks were derived from a heterogeneous arc-crust with distinct crustal histories on either side of the GGB. The voluminous similar to 2.56 Ga granitic magmatism surrounding the GGB in the WDC, in addition to the known similar to 2.61 and 2.56-2.52 Ga felsic magmatism supports a number of short-lived, episodic crustal growth events within the Dharwar Craton during the Neoarchean over a period of similar to 100 m.y. Short-lived episodic crustal growth during the Archean, typically within the time scale of few million years marks the distinction with long-lived modern-style subduction processes; these variations are often attributed to hotter Archean mantle and prevailing geodynamic regime. (C) 2014 Elsevier B.V. All rights reserved.