It has been generally recognized that the basic “fold,” or shape, of a protein must be conserved across species, because there is a tight correspondence between structure and function. Proteins that retain the same function across very different species – generally the case with orthologs – are expected to keep the same fold.
一般认为，蛋白质的基本“折叠”（即形状）应该不随物种的改变而改变，因为蛋白质的结构与功能紧密相关。不同物种间功能相同的蛋白质——大致上与同源体相同——被认为具有相同的折叠。