Investigating Substrate Specificity of Sortases

研究分选酶的底物特异性

• 批准号: 7000253
• 负责人: Valerie A Villareal
• 金额: $ 2.96万
• 依托单位: UNIVERSITY OF CALIFORNIA LOS ANGELES
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-09-01 至 2010-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7000253
• 关键词: Staphylococcus aureus; Streptococcus pyogenes; antibacterial agents; bacteria infection mechanism; bacterial proteins; cell adhesion; electroporation; enzyme activity; enzyme inhibitors; enzyme linked immunosorbent assay; enzyme substrate; gram positive bacteria; high throughput technology; host organism interaction; molecular shape; nuclear magnetic resonance spectroscopy; polymerase chain reaction; predoctoral investigator; protein sequence; protein structure function; transferase; transpeptidation; virulence

DESCRIPTION (provided by applicant): Gram-positive bacteria are the causative agents of many nosocomial infections and diseases including osteomyelitis and pneumonia. The majority of Gram-positive bacteria harbor sortases, which are transpeptidases that recognize a short peptide sequence found near the C-terminus of proteins. Proteins harboring this recognition motif are subsequently anchored to the peptidoglycan and are required to establish infection by acting as adhesins or by mediating evasion from the host's immune system. One such sortase, SrtA, recognizes and processes the sequence, Leu-Pro-X-Thr-Gly motif in vitro. Bioinformatics analyses predict SrtA may recognize LPXTG variants as well as a 6th amino acid. Another family of sortases, subfamily-3, is also predicted to process similar recognition motifs. We propose to determine the substrate specificity of these sortases to understand in vivo recognition. We will also use NMR spectroscopy to solve the structures of the sortase-substrate complexes. Results from this project will afford details on how these transpeptidases function and will identify residues participating in recognition. This work will complement ongoing sortase inhibitor studies.

描述（由申请人提供）：革兰氏阳性菌是许多医院感染和疾病（包括骨髓炎和肺炎）的病原体。大多数革兰氏阳性细菌都含有分选酶，它们是识别蛋白质 C 末端附近的短肽序列的转肽酶。带有这种识别基序的蛋白质随后被锚定到肽聚糖上，并需要通过充当粘附素或介导宿主免疫系统的逃避来建立感染。其中一种分选酶 SrtA 可在体外识别并处理序列 Leu-Pro-X-Thr-Gly 基序。生物信息学分析预测 SrtA 可能识别 LPXTG 变体以及第六个氨基酸。另一个分选酶家族，subfamily-3，也预计能处理类似的识别基序。我们建议确定这些分选酶的底物特异性以了解体内识别。我们还将使用核磁共振波谱来解析分选酶-底物复合物的结构。该项目的结果将提供有关这些转肽酶如何发挥作用的详细信息，并将识别参与识别的残基。这项工作将补充正在进行的分选酶抑制剂研究。