upstream downstream

Genetics as it applies to evolution, molecular biology, and medical aspects.

Moderators: Leonid, amiradm, BioTeam

Post Reply
youknowwho1
Garter
Garter
Posts: 7
Joined: Sat Aug 23, 2008 8:50 pm

upstream downstream

Post by youknowwho1 » Tue Aug 26, 2008 9:19 am

"cis elements upstream of binding site" what does upstream mean?

blcr11
Viper
Viper
Posts: 672
Joined: Fri Mar 30, 2007 4:23 am

Re: upstream downstream

Post by blcr11 » Tue Aug 26, 2008 12:13 pm

Transcription runs 5' (start) to 3' (end). Anything that sits 5' to the start site is outside the transcribed region but lies "upstream" of the start site. A cis-acting element must act on the same segment of "gene" (it usually is DNA, but it can be RNA) to which it is itself a part of, so a cis-acting upstream element is something (a promoter or enhancer, say) that lies 5' to the transcribed gene, and is involved in the regulation of the gene (occasionally genes, plural) immediately in front of it--that at least covers the most common instances of upstream cis-acting elements.

I was assuming this was a question about transcription. If the "binding site" is something other than a promoter or repressor binding site, then whatever process this is, must have some sense of directionality to it. Upstream would be something "before" the site and downstream would be something "after" the site, if that makes any sense.

Post Reply

Who is online

Users browsing this forum: No registered users and 4 guests