Background:The primary function of the abundant and highly conserved protein TCTP is not clear. Results: TCTP binds to a conserved central acidic region of eukaryotic elongation factor 1B␣/␤/␦. Conclusion: The binding of TCTP to eukaryotic elongation factor 1B is evolutionarily conserved. Significance: The interaction with eEF1B represents a primary function of TCTP.

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The Ga'erqiong-Galale skarn-porphyry copper-gold ore-concentrated area is located in the western part of the Bangong-Nujiang suture zone north of the Lhasa Terrane. This paper conducted a systematic study on the magmatism and metallogenic effect in the ore-concentrated area using techniques of isotopic geochronology, isotopic geochemistry and lithogeochemistry. According to the results, the crystallization age of quartz diorite (ore-forming mother rock) in the Ga'erqiong deposit is 87.1 ± 0.4 Ma, which is later than the age of granodiorite (ore-forming mother rock) in the Galale deposit (88.1 ± 1.0 Ma). The crystallization age of granite porphyry (GE granite porphyry) in the Ga'erqiong deposit is 83.2 ± 0.7 Ma, which is later than the age of granite porphyry (GL granite porphyry) in the Galale deposit (84.7 ± 0.8 Ma).The quartz diorite, granodiorite, GE granite porphyry and GL granite porphyry both main shows positive εHf(t) values, suggesting that the magmatic source of the main intrusions in the ore-concentrated area has the characteristics of mantle source region. The Re-Os isochron age of molybdenite in the Ga'erqiong district is 86.9 ± 0.5 Ma, which is later than the mineralization age of the Galale district (88.6 ± 0.6 Ma). The main intrusive rocks in the ore-concentrated area have similar lithogeochemical characteristics, for they both show the relative enrichment in large-ion lithophile elements(LILE: Rb, Ba, K, etc.), more mobile highly incompatible lithophile elements(HILE: U, Th) and relatively depleted in high field strength elements (HFSE: Nb, Ta, Zr, Hf, etc.), and show the characteristics of magmatic arc. The studies on the metal sulfides' S and Pb isotopes and Re content of molybdenite indicate that the metallogenic materials of the deposits in the ore-concentrated area mainly come from the mantle source with minor crustal source contamination. Based on the regional tectonic evolution process, this paper points out that the Ga'erqiong-Galale copper-gold ore-concentrated area is the typical product of the Late Cretaceous magmatism and metallogenic event in the collision stage of the Bangong-Nujiang suture zone.

Many important proteins undergo pH-dependent conformational changes resulting in “on-off” switches for protein function, which are essential for regulation of life processes and have wide application potential. Here, we report a pair of cellulosomal assembly modules, comprising a cohesin and a dockerin from Clostridium acetobutylicum, which interact together following a unique pH-dependent switch between two functional sites rather than on-off states. The two cohesin-binding sites on the dockerin are switched from one to the other at pH 4.8 and 7.5 with a 180° rotation of the bound dockerin. Combined analysis by nuclear magnetic resonance spectroscopy, crystal structure determination, mutagenesis, and isothermal titration calorimetry elucidates the chemical and structural mechanism of the pH-dependent switching of the binding sites. The pH-dependent dual-binding-site switch not only represents an elegant example of biological regulation but also provides a new approach for developing pH-dependent protein devices and biomaterials beyond an on-off switch for biotechnological applications.

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The Dahutang tungsten polymetallic ore field is located north of the Nanling W–Sn polymetallic metallogenic belt and south of the Middle–Lower Yangtze River Valley Cu–Mo–Au–Fe porphyry‐skarn belt. It is a newly discovered ore field, and probably represents the largest tungsten mineralization district in the world. The Shimensi deposit is one of the mineral deposits in the Dahutang ore field, and is associated with Yanshanian granites intruding into a Neoproterozoic granodiorite batholith. On the basis of geologic studies, this paper presents new petrographic, microthermometric, laser Raman spectroscopic and hydrogen and oxygen isotopic studies of fluid inclusions from the Shimensi deposit. The results show that there are three types of fluid inclusions in quartz from various mineralization stages: liquid‐rich two‐phase fluid inclusions, vapor‐rich two‐phase fluid inclusions, and three‐phase fluid inclusions containing a solid crystal, with the vast majority being liquid‐rich two‐phase fluid inclusions. In addition, melt and melt‐fluid inclusions were also found in quartz from pegmatoid bodies in the margin of the Yanshanian intrusion. The homogenization temperatures of liquid‐rich two‐phase fluid inclusions in quartz range from 162 to 363°C and salinities are 0.5wt%–9.5wt% NaCl equivalent. From the early to late mineralization stages, with the decreasing of the homogenization temperature, the salinity also shows a decreasing trend. The ore‐forming fluids can be approximated by a NaCl–H2O fluid system, with small amounts of volatile components including CO2, CH4 and N2, as suggested by Laser Raman spectroscopic analyses. The hydrogen and oxygen isotope data show that δDV.SMOW values of bulk fluid inclusions in quartz from various mineralization stages vary from –63.8‰ to –108.4‰, and the δ18OH2O values calculated from the δ18OV‐SMOW values of quartz vary from –2.28‰ to –7.21‰. These H–O isotopic data are interpreted to indicate that the ore‐forming fluids are mainly composed of magmatic water in the early stage, and meteoric water was added and participated in mineralization in the late stage. Integrating the geological characteristics and analytical data, we propose that the ore‐forming fluids of the Shimensi deposit were mainly derived from Yanshanian granitic magma, the evolution of which resulted in highly differentiated melt, as recorded by melt and melt‐fluid inclusions in pegmatoid quartz, and high concentrations of metals in the fluids. Cooling of the ore‐forming fluids and mixing with meteoric water may be the key factors that led to mineralization in the Dahutang tungsten polymetallic ore field.

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