Characterization of Xpr (Xpct) reveals instability but no effects on X-chromosome pairing or Xist expression.

X-chromosome inactivation balances X-chromosome dosages in male and female mammals by transcriptionally repressing one X in the female sex. Proper counting and the mutually exclusive choice of active X and inactive X have been hypothesized to involve X-chromosome crosstalk via homologous chromosome pairing. Transient pairing of two female Xs requires noncoding Tsix and Xite.

A highly distinctive mechanical property found in the majority of human promoters and its transcriptional relevance.

A recent study revealed that TATA boxes and initiator sequences have a common anomalous mechanical property, i.e. they comprise distinctive flexible and rigid sequences when compared with the other parts of the promoter region.

Core promoter elements of eukaryotic genes have a highly distinctive mechanical property.

In spite of the abundant data on DNA sequence, the mechanical aspects of promoter DNA remain poorly understood. We classified 1871 human and 196 mouse RNA polymerase II promoters and investigated average flexibility profiles of the human promoters containing either a TATA box or an initiator (Inr) sequence only. Here, we show that TATA boxes and Inr sequences have a common anomalous mechanical property: they are comprised of distinctively flexible and rigid sequences, compared with the other parts of the promoter region.

Left-handedly curved DNA regulates accessibility to cis-DNA elements in chromatin.

There is little information on chromatin structure that allows access of trans-acting transcription factors. Logically, the target DNA elements become accessible by either exposing themselves towards the environment on the surface of the nucleosome, or making the regulatory region free of the nucleosome. Here, we demonstrate that curved DNA that mimics a negative supercoil can play both roles in the promoter region.