L-pyrrolysine Chemical and Structural Biology

描述(申请人提供)：在前一个资助周期中，我们确定了位于巴氏杆菌单甲胺甲基转移酶中的UAG密码子编码了一种新的氨基酸。根据其在天然络合物和羟胺络合物中的电子密度，我们确定该氨基酸是4-甲基-(4R，5R)-吡咯啉-5-羧酸，连接在赖氨酸的表观氮上。根据其组成，我们将其命名为L-吡咯赖氨酸。Krzycki小组随后发现了一个琥珀色的编码tRNA(Pyl)和一个新的将L-吡咯赖氨酸加载到tRNA(Pyl)上的新型L-吡咯烷基-tRNA合成酶Pyls，这有力地证明了吡咯赖氨酸是自然界中第22个遗传编码的氨基酸。 在这一资金周期中，我们建议继续努力了解L-吡咯赖氨酸的功能作用及其整合到蛋白质中的机制。这包括：(1)含蛋白质的L-吡咯赖氨酸的结构研究；(2)L-吡咯赖氨酸与蛋白质结合的结构研究；(3)L-吡咯赖氨酸及其类似物的化学合成。

DESCRIPTION (provided by applicant): During the previous funding cycle, we determined that a UAG-codon, located in the M. barkeri monomethylamine methyltransferase, encoded a new amino acid. Based on its electron density in the native and hydroxylamine complexes, we determined that the amino acid is 4-methyl-(4R,5R)-pyrroline-5- carboxylate, attached to the epsilon nitrogen of lysine. Based on its composition, we named this amino acid, L-pyrrolysine. The subsequent identification, by the Krzycki group, of an amber decoding tRNA(Pyl), and a novel L-pyrrolysyl-tRNA synthetase PylS, that loads L-pyrrolysine onto tRNA(Pyl) make a strong case for Lpyrrolysine being the 22nd genetically-encoded amino acid in nature. During this funding cycle, we propose to continue our efforts in understanding L-pyrrolysine's functional role and its mechanism of incorporation into proteins. This will include: (1) structural studies of L-pyrrolysine containing proteins, (2) structural studies involved in L-pyrrolysine incorporation into protein, and (3) chemical synthesis of L-pyrrolysine and its analogs.