分类: 生物学 >> 生物进化论 提交时间: 2024-03-20
摘要: Here we report a new form of amphicyonid from an uncertain locality in the LinxiaBasin. The derived dental traits imply an affinity to Magericyon, previously known from Europe and possibly southern Asia. The specimen suggests a higher diversity of amphicyonids in eastern Asia than previously thought, and more discovery with stratigraphic information will be needed to elucidate the evolution of Amphicyonidae in eastern Asia.
分类: 生物学 >> 生物物理学 >> 生物物理、生物化学与分子生物学 提交时间: 2016-05-15
摘要: The cyclic nucleotide-binding (CNB)-like protein (CNB-L) from Brucella abortus shares sequence homology with CNB domain-containing proteins. We determined the crystal structure of CNB-L at 2.0 angstrom resolution in the absence of its C-terminal helix and nucleotide. The 3D structure of CNB-L is in a twofold symmetric form. Each protomer shows high structure similarity to that of cGMP-binding domain-containing proteins, and likely mimics their nucleotide-free conformation. A key residue, Glu17, mediates the dimerization and prevents binding of cNMP to the canonical ligand-pocket. The structurally observed dimer of CNB-L is stable in solution, and thus is likely to be biologically relevant. (C) 2015 Elsevier Inc. All rights reserved.