کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
2819635 1569931 2007 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Protein fold and structure in the truncated (2/2) globin family
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی ژنتیک
پیش نمایش صفحه اول مقاله
Protein fold and structure in the truncated (2/2) globin family
چکیده انگلیسی

Analysis of amino acids sequences and protein folds has recently unraveled the structural bases and details of several proteins from the recently discovered “truncated hemoglobin” family. The analysis here presented, in agreement with previous surveys, shows that truncated hemoglobins can be classified in three main groups, based on their structural properties. Crystallographic analyses have shown that all three groups adopt a 2-on-2 α-helical sandwich fold, resulting from apparent editing of the classical 3-on-3 α-helical sandwich of vertebrate and invertebrate conventional globins. Specific structural features distinguish each of the three groups. Among these, a protein matrix tunnel system is typical of group I, a Trp residue at the G8 topological site is conserved in groups II and III, and TyrB10 is almost invariant through the three groups. A strongly intertwined network of hydrogen bonds stabilizes the heme bound ligand, despite variability of the heme distal residues observed in the different proteins considered. Details of ligand recognition in the three groups are discussed at the light of residue conservation and of differing ligand diffusion pathways to the heme. Based on structural analyses of the family-specific fold, we endorse a recent proposal of leaving the “truncated hemoglobins” term, that does not represent properly the observed 2-on-2 α-helical sandwich fold, and adopting the simple “2/2Hb” term to concisely address this protein family.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Gene - Volume 398, Issues 1–2, 15 August 2007, Pages 2–11
نویسندگان
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