negative elongation

negative elongation

[′neg·əd·iv ‚ē‚lȯŋ′gā·shən]
(crystallography)
In a section of an anisotropic crystal, a sign of elongation that is parallel to the faster of the two plane-polarized rays.
References in periodicals archive ?
We will use an integrated structural biology approach combining X-ray crystallography, cryo-electron microscopy, and crosslinking, to obtain the first atomic structure of a mammalian Pol II enzyme (aim 1), the structure of the negative elongation factor NELF (aim 2), which is required for promoter-proximal pausing by mammalian Pol II, and the threedimensional architecture of the promoter-proximally paused Pol II complex (aim 3) containing the multiprotein pausing factors NELF and DSIF, and eventually also the pause release factor p-TEFb.