Zuckerkandl E
J Mol Evol. 1986;24(1-2):12-27. doi: 10.1007/BF02099947.
Certain as yet poorly defined functions of DNA appear to involve collectively domain-sized sequences. It is proposed that most sequence segments within a domain may be either functionally superfluous or instrumental, depending on how many related sequences are present in the domain. When redundant and functionally dispensable, such DNA segments presumably still have to conform to compositional or sequence-motif patterns that characterize the domain. In its relations with neighboring sequences, such DNA is required to be "polite." Polite DNA is DNA that, without being crucially involved in function, is subject to constraints of conformity and, through its base composition, respects a function for which it is not required. This concept is developed by contrasting the distribution of specific and general functions over DNA with this distribution as found in proteins and by distinguishing functional compatibility from pivotal functionality. The sequence constraints to which heterochromatin as well as, apparently, long interspersed repetitive sequences are known to be subject seem to imply that DNA, even when it does not carry out a pivotal function, is indeed, at the very least, required to be polite.
DNA某些尚未明确界定的功能似乎共同涉及结构域大小的序列。有人提出，一个结构域内的大多数序列片段可能在功能上是多余的或起作用的，这取决于该结构域中存在多少相关序列。当这些DNA片段冗余且在功能上可有可无时，它们可能仍需符合表征该结构域的组成或序列基序模式。在与相邻序列的关系中，这种DNA需要“有礼貌”。有礼貌的DNA是指那些虽然不关键地参与功能，但受到一致性约束，并通过其碱基组成尊重一种它并非必需的功能的DNA。通过将DNA上特定和一般功能的分布与蛋白质中发现的这种分布进行对比，并区分功能兼容性和关键功能，这一概念得以发展。已知异染色质以及显然还有长散在重复序列所受的序列约束似乎意味着，DNA即使不执行关键功能，实际上至少也需要有礼貌。
