Characterization of NopP, a type III secreted effector of Rhizobium sp. strain NGR234
Characterization of NopP, a type III secreted effector of Rhizobium sp. strain NGR234
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DOI：
10.1128/jb.186.14.4774-4780.2004
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发表时间：
2004-07-01
影响因子：
3.2
通讯作者：
Perret, X
中科院分区：
文献类型：
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作者：
Ausmees, N;Kobayashi, H;Perret, X
根瘤菌NGR234共生质粒pNGR234a编码的第三型分泌系统（TTSS）负责类黄酮和nodd1依赖性的结瘤外蛋白（Nops）分泌。取消所有或特定Nops的分泌会显著改变NGR234在许多宿主上的结瘤能力。在密切相关的菌株fredii Rhizobium USDA257中，TTSS的失活改变了突变体的宿主范围，使其包括改良的甘氨酸mar品种McCall。为了评估单个ttss分泌蛋白对与豆科植物共生的影响，进行了各种鉴定nop基因的尝试。从凝胶中纯化的肽氨基端测序用于鉴定NopA， NopL和NopX，但未能鉴定SR3， USDA257的ttss依赖性产物。通过噬菌体展示和识别SR3的抗体，鉴定出NGR234对应的蛋白为NopP。与NopL一样，NopP也是由NGR234的TTSS分泌的效应物，根据豆科寄主的不同，它对结瘤的影响可能是有害的，也可能是有益的，也可能影响很小。
The type three secretion system (TTSS) encoded by pNGR234a, the symbiotic plasmid of Rhizobium sp. strain NGR234, is responsible for the flavonoid- and NodD1-dependent secretion of nodulation outer proteins (Nops). Abolition of secretion of all or specific Nops significantly alters the nodulation ability of NGR234 on many of its hosts. In the closely related strain Rhizobium fredii USDA257, inactivation of the TTSS modifies the host range of the mutant so that it includes the improved Glycine mar variety McCall. To assess the impact of individual TTSS-secreted proteins on symbioses with legumes, various attempts were made to identify nop genes. Amino-terminal sequencing of peptides purified from gels was used to characterize NopA, NopL, and NopX, but it failed to identify SR3, a TTSS-dependent product of USDA257. By using phage display and antibodies that recognize SR3, the corresponding protein of NGR234 was identified as NopP. NopP, like NopL, is an effector secreted by the TTSS of NGR234, and depending on the legume host, it may have a deleterious or beneficial effect on nodulation or it may have little effect.