Wedel A B
Department of Biology, University of California, Santa Cruz 95064, USA.
Trends Biotechnol. 1996 Dec;14(12):459-65. doi: 10.1016/S0167-7799(96)10066-4.
Novel RNA enzymes, or ribozymes, are sought in large pools of random RNA sequences. Because of the large number of random positions in an individual pool molecule, only a vanishingly small fraction of the possible sequences are actually present. Even so, increasing the length of the individual pool molecules significantly increases the probability of finding a particular complex ribozyme. Because ribozymes are typically composed of conserved sequences interleaved with regions that can vary in sequence and length, a longer molecule allows a greater number of possible arrangements of a given ribozyme motif, increasing the likelihood that it will be present in the pool. Once a ribozyme motif has been found, rational and irrational optimization techniques can be used to identify related ribozyme sequences with greater activity.
人们在大量随机RNA序列中寻找新型RNA酶，即核酶。由于单个文库分子中存在大量随机位置，实际存在的可能序列只是极小的一部分。即便如此，增加单个文库分子的长度会显著提高找到特定复杂核酶的概率。因为核酶通常由保守序列与序列和长度可变的区域交错组成，更长的分子允许给定核酶基序有更多可能的排列方式，从而增加其出现在文库中的可能性。一旦发现了一个核酶基序，就可以使用合理和不合理的优化技术来鉴定具有更高活性的相关核酶序列。
