L-pyrrolysine Chemical and Structural Biology

描述（由申请人提供）：在上一个资助周期中，我们确定位于巴氏分枝杆菌单甲基胺甲基转移酶中的uag密码子编码了一个新的氨基酸。根据其在天然和羟胺配合物中的电子密度，我们确定该氨基酸是4-甲基-(4R,5R)-吡咯-5-羧酸盐，与赖氨酸的ε氮相连。根据它的组成，我们将这种氨基酸命名为l -吡咯赖氨酸。Krzycki小组随后鉴定出琥珀色解码tRNA（Pyl）和一种新的L-pyrrolysyl-tRNA合成酶PylS，该合成酶将l- pyrlysine装载到tRNA（Pyl）上，这有力地证明了lpyrlysine是自然界中第22个遗传编码的氨基酸。

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.