Hartman H
Institute for Advanced Studies in Biology, Berkeley, CA 94707, USA.
J Mol Evol. 1995 May;40(5):541-4. doi: 10.1007/BF00166623.
The most primitive code is assumed to be a GC code: GG coding for glycine, CC coding for proline, GC coding for alanine, CG coding for "arginine." The genetic code is assumed to have originated with the coupling of glycine to its anticodon CC mediated by a copper-montmorillonite. The polymerization of polyproline followed when it was coupled to its anticodon GG. In this case the aminoacyl-tRNA synthetase was a copper-montmorillonite. The first membrane is considered to be a beta sheet formed from polyglycine. As the code grew more complicated, the alternative hydrophobic-hydrophilic polypeptide (alanine-"arginine") was coded for by the alternating CG copolymer. This alternating polypeptide (ala-"arg") began to function as both a primitive membrane and as an aminoacyl-tRNA synthetase. The evolution of protein structure is tightly coupled to the evolution of the membrane. The alpha helix was evolved as lipids became part of the structure of biological membranes. The membrane finally became the fluid mosaic structure that is now universal.
最原始的密码被假定为GC密码：GG编码甘氨酸，CC编码脯氨酸，GC编码丙氨酸，CG编码“精氨酸”。遗传密码被认为起源于由铜蒙脱石介导的甘氨酸与其反密码子CC的偶联。当多聚脯氨酸与其反密码子GG偶联时，随后发生了多聚脯氨酸的聚合。在这种情况下，氨酰-tRNA合成酶是铜蒙脱石。第一个膜被认为是由聚甘氨酸形成的β折叠。随着密码变得更加复杂，交替的疏水-亲水多肽（丙氨酸-“精氨酸”）由交替的CG共聚物编码。这种交替的多肽（ala-“arg”）开始既作为原始膜又作为氨酰-tRNA合成酶发挥作用。蛋白质结构的进化与膜的进化紧密相关。随着脂质成为生物膜结构的一部分，α螺旋得以进化。膜最终变成了现在普遍存在的流体镶嵌结构。
