I suspect everyone is refering to Rost's "twilight zone" in sequence similarity where homology modeling trials had better be avoided. If so, the "twilight zone" would rather correspond to any indefinite or transitional condition(s) with no applicable or ever relevant binary constraint(s).
Nadir Mrabet -- Pr. Nadir T. Mrabet Cellular & Molecular Biochemistry INSERM U-724 UHP - Nancy 1, School of Medicine 54505 Vandoeuvre-les-Nancy Cedex France Tel : +33 (0)3.83.68.32.73 Fax : +33 (0)3.83.68.32.79 E-mail : [EMAIL PROTECTED] Selon Dima Klenchin <[EMAIL PROTECTED]>: > >>to models built on low-homology structures. > > > >since i'm currently preparing my bioinformatics lectures for next week's > >teaching, i might as well be a Besserwisser and point out that homology, > >much like pregnancy and death, is a binary concept. i'm sure artem knows > >this and simply mistyped "low sequence identity" > > Well, although it is off-topic: > > Random House Unabridged Dictionary > Homologous > 1. Corresponding or similar in position, value, structure, or function. > > So if you insist that homologous is a binary concept then you should be > able to come up with the exact boundary between what's homologous and > what's not. > What is it? 10% sequence identity? Less? More? Because if such a boundary > cannot be defined then everything can be homologous to everything - it's > all in the eye of the beholder. And if so, then the binary concept of > homology is either meaningless or incorrect. > > Ergo: arguing about definitions of terms used to describe continua is not > very productive in science (cf. "species", "sea/ocean", "hill/mountain"). > > Dima >
