Granell Meritxell, Namura Mikiyoshi, Alvira Sara, Kanamaru Shuji, van Raaij Mark J
Departmento de Estructura de Macromoleculas, Centro Nacional de Biotecnologia (CNB-CSIC), Calle Darwin 3, E-28049 Madrid, Spain.
Department of Life Science and Technology, Tokyo Institute of Technology, M6-11 2-12-1 Ookayama, Meguro-ku Tokyo 152-8550, Japan.
Viruses. 2017 Jun 30;9(7):168. doi: 10.3390/v9070168.
Long tail fibers of bacteriophage T4 are formed by proteins gp34, gp35, gp36, and gp37, with gp34 located at the phage-proximal end and gp37 at the phage-distal, receptor-binding end. We have solved the structure of the carboxy-terminal region of gp34, consisting of amino acids 894-1289, by single-wavelength anomalous diffraction and extended the structure to amino acids 744-1289 using data collected from crystals containing longer gp34-fragments. The structure reveals three repeats of a mixed α-β fibrous domain in residues 744 to 877. A triple-helical neck connects to an extended triple β-helix domain (amino acids 900-1127) punctuated by two β-prism domains. Next, a β-prism domain decorated with short helices and extended β-helices is present (residues 1146-1238), while the -terminal end is capped with another short β-helical region and three β-hairpins. The structure provides insight into the stability of the fibrous gp34 protein.
噬菌体T4的长尾纤维由gp34、gp35、gp36和gp37蛋白构成，其中gp34位于噬菌体近端，gp37位于噬菌体远端的受体结合端。我们通过单波长反常衍射解析了gp34羧基末端区域（由894至1289位氨基酸组成）的结构，并利用从含有更长gp34片段的晶体收集的数据将该结构扩展至744至1289位氨基酸。该结构揭示了744至877位残基中混合α-β纤维结构域的三个重复序列。一个三螺旋颈部连接到一个延伸的三β-螺旋结构域（900至1127位氨基酸），该结构域由两个β-棱柱结构域间断。接下来，存在一个装饰有短螺旋和延伸β-螺旋的β-棱柱结构域（1146至1238位残基），而末端则由另一个短β-螺旋区域和三个β-发夹结构封闭。该结构为纤维状gp34蛋白的稳定性提供了见解。
