Laboratório Nacional de Luz Sincrotron (LNLS), Campinas, SP, Brazil.
Proteome Sci. 2010 Nov 9;8:55. doi: 10.1186/1477-5956-8-55.
Citrus canker is a disease caused by Xantomonas citri subsp.citri (Xac), and has emerged as one of the major threats to the worldwide citrus crop because it affects all commercial citrus varieties, decreases the production and quality of the fruits and can spread rapidly in citrus growing areas. In this work, the first proteome of Xac was analyzed using two methodologies, two-dimensional liquid chromatography (2D LC) and tandem mass spectrometry (MS/MS).
In order to gain insight into the metabolism of Xac, cells were grown on two different media (NB - Nutrient Broth and TSE - Tryptone Sucrose broth enriched with glutamic acid), and proteins were proteolyzed with trypsin and examined by 2D LC-MS/MS. Approximately 39% of all predicted proteins by annotation of Xac were identified with their component peptides unambiguously assigned to tandem mass spectra. The proteins, about 1,100, were distributed in all annotated functional categories.
This is the first proteomic reference map for the most aggressive strain of Xanthomonas pathogen of all orange varieties. The compilation of metabolic pathways involved with bacterial growth showed that Xac expresses a complete central and intermediary metabolism, replication, transcription and translation machineries and regulation factors, distinct membrane transporters (ABC, MFS and pumps) and receptors (MCP, TonB dependent and metabolites acquisition), two-component systems (sensor and regulatory components) and response regulators. These data corroborate the growth curve in vitro and are the first reports indicating that many of these genome annotated genes are translated into operative in Xac. This proteomic analysis also provided information regarding the influence of culture medium on growth and protein expression of Xac.
柑橘溃疡病是由柑橘溃疡病菌（Xac）引起的一种疾病，已成为全球柑橘作物的主要威胁之一，因为它影响所有商业柑橘品种，降低果实的产量和质量，并能在柑橘种植区迅速传播。在这项工作中，使用二维液相色谱（2D LC）和串联质谱（MS/MS）两种方法分析了 Xac 的第一个蛋白质组。
为了深入了解 Xac 的代谢情况，细胞在两种不同的培养基（NB-营养肉汤和 TSE-富含谷氨酸的胰蛋白胨蔗糖肉汤）上生长，用胰蛋白酶对蛋白质进行蛋白水解，并通过 2D LC-MS/MS 进行检查。通过 Xac 的注释预测了大约 39%的所有蛋白质，其组成肽被明确分配到串联质谱中。这些蛋白质约有 1100 个，分布在所有注释的功能类别中。
这是所有橙色品种柑橘黄单胞菌最具侵略性菌株的第一个蛋白质组参考图谱。涉及细菌生长的代谢途径的编制表明，Xac 表达了完整的中心和中间代谢、复制、转录和翻译机制以及调节因子、独特的膜转运蛋白（ABC、MFS 和泵）和受体（MCP、TonB 依赖性和代谢物获取）、双组分系统（传感器和调节成分）和响应调节剂。这些数据与体外生长曲线相符，也是首次报道表明，许多基因组注释基因被翻译成 Xac 的可操作基因。这项蛋白质组学分析还提供了关于培养基对 Xac 生长和蛋白质表达影响的信息。
