Bacterial N-Acetyltransferases: Resistance to Regulation

细菌 N-乙酰转移酶：对调节的抵抗

• 批准号: 6889272
• 负责人: John S Blanchard
• 金额: $ 45.24万
• 依托单位: ALBERT EINSTEIN COLLEGE OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-05-01 至 2009-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6889272
• 关键词: Mycobacterium tuberculosis; SDS polyacrylamide gel electrophoresis; Salmonella; acetylation; acyltransferase; aminoglycoside antibiotics; bacterial proteins; drug resistance; enzyme activity; enzyme structure; enzyme substrate; mass spectrometry; microorganism growth; molecular cloning; protein protein interaction; protein structure function; surface plasmon resonance

DESCRIPTION (provided by applicant): The long term goals of the present application are to determine the catalytic mechanisms, three-dimensional structures and physiological function of bacterial N-acetyltransferases. As a result of the intensive genome sequencing efforts of the last decade, and modern bioinformatics approaches to the identification of protein superfamilies, some 10,000 members of the GCN5-related N-acetyltransferase (GNAT) family have been identified. In bacteria, these include family members whose function is (1) the acetylation of aminoglycoside antibiotics, (2) the N-terminal acetylation of the ribosomal proteins S5, S18 and L12, and (3) unknown. The specific aims of the current application are organized to address these three classes of bacterial N-acetyltransferases. Of the thousands of encoded bacterial GNAT proteins, only three are known to acetylate proteins. They are encoded by the rimI, rimJ and rimL genes that are presumed to function in the alpha-N-acetylation of their cognate substrates; the ribosomal S5, S18 and L12 proteins, respectively. The state of acetylation of the latter protein is correlated with bacterial growth, suggesting that reversible enzymatic acetylation/deacetylation is important in controlling bacterial growth. Bacterial resistance to antibiotics is a clinically significant problem that threatens current paradigms of antibacterial chemotherapy. Aminoglycosides were one of the first classes of antibiotics used in the treatment of bacterial infections, and act by specifically inhibiting bacterial protein synthesis. Clinically, the vast majority of resistance is due to the expression of enzymes that modify the drug, including enzymes that phosphorylate, adenylate or acetylate aminoglycosides. Of these three activities, the expression of aminoglycoside N-acetyltransferases is most prevalent in clinical isolates. We will continue our examination of bacterial aminoglycoside N-acetyltransferases. Finally, in the genomes of the important human pathogens, Salmonella typhimurium and Myeobaeterium tuberculosis, there are 29 and 20, respectively, predicted GNAT family members, for which only 8 and 4, respectively, have putative, annotated functions, most of which include the functions discussed above. We will develop reagents and methods to define the physiological substrates for these enzymes.

描述（由申请人提供）：本应用的长期目标是确定细菌N-乙酰基转移酶的催化机制，三维结构和生理功能。由于过去十年的强化基因组测序工作，现代生物信息学方法可以鉴定出蛋白质超家族，因此已经鉴定出约有10,000名与GCN5相关的N-乙酰基转移酶（GNAT）家族的成员。 在细菌中，其中包括（1）氨基糖苷抗生素的乙酰化，（2）核糖体蛋白S5，S18和L12的N末端乙酰化的乙酰化，以及（3）未知。组织了当前应用的具体目的，以解决这三类细菌N-乙酰基转移酶。 在成千上万的编码细菌GNAT蛋白中，只有三种是乙酰蛋白。它们由RIMI，RIMJ和RIML基因编码，这些基因被认为在其同源底物的α-N-乙酰化中发挥作用。核糖体S5，S18和L12蛋白分别。后一种蛋白的乙酰化状态与细菌生长相关，表明可逆酶乙酰化/脱乙酰化对于控制细菌生长很重要。 细菌对抗生素的耐药性是一个临床上重要的问题，它威胁了当前的抗菌化学疗法范例。氨基糖苷是用于治疗细菌感染的首批抗生素之一，并通过特别抑制细菌蛋白质合成来起作用。从临床上讲，绝大多数耐药性是由于酶的表达，包括磷酸化，腺苷酸或乙酰酸氨基糖苷的酶。在这三个活动中，氨基糖苷N-乙酰转移酶的表达最为普遍。我们将继续研究细菌氨基糖苷N-乙酰基转移酶。 最后，在重要的人类病原体的基因组中，鼠伤寒沙门氏菌和结核孤r，分别有29和20，预测了GNAT家族成员，其中只有8和4具有假定的，具有注释的功能，其中大多数包括上面讨论的功能。我们将开发试剂和方法来定义这些酶的生理底物。