TELOMERE - and everything about it.

Debate and discussion of any biological questions not pertaining to a particular topic.

Moderators: honeev, Leonid, amiradm, BioTeam

Post Reply
telomere
Garter
Garter
Posts: 4
Joined: Mon Jun 26, 2006 1:51 pm

TELOMERE - and everything about it.

Post by telomere » Mon Jun 26, 2006 2:08 pm

'TELOMERE' - as most of us know about it - is present at the ends of chromosomes and have some specialized structure and functions, which we would be discussing. Hope you would have a nice time here.
Last edited by telomere on Mon Jun 26, 2006 3:02 pm, edited 1 time in total.

telomere
Garter
Garter
Posts: 4
Joined: Mon Jun 26, 2006 1:51 pm

Post by telomere » Mon Jun 26, 2006 2:24 pm

I would like to start with the most astonising feature described for the telomeric DNA spacial structure - t-loop - as named by the authors of the classical Cell paper in 1999, Vol. 97, 503–514. The paper is classical in the context of the discovery of a cross-over 'holliday-junction' like structure for the eukaryotic chromosomal ends. But since similar structures are not well-documented - there lies a big question of interest - how does the replicative machinery distinguises it and replicates the telomere.

telomere
Garter
Garter
Posts: 4
Joined: Mon Jun 26, 2006 1:51 pm

Post by telomere » Mon Jun 26, 2006 2:25 pm

Interestingly, telomereric 3'-overhang, which is single-stranded DNA and is guanine-rich sequence*, and has been shown to form G-quadruplex - a higher secondary structure, has not been talked about!!!!

*for human and many other vertebrates is TTAGGG repeat (for humans the average is 200-300b)
Last edited by telomere on Mon Jun 26, 2006 2:44 pm, edited 1 time in total.

telomere
Garter
Garter
Posts: 4
Joined: Mon Jun 26, 2006 1:51 pm

Post by telomere » Mon Jun 26, 2006 2:26 pm

why 'G-quadruplex' - coz once formed, its very stable. Additionaly, if the telomere end folds back to form the t-loop, as proposed in that paper, it still displaces the guanine rich sequence of the duplex DNA from the telomere, and keeps is as an overhang, which is definitely not an energetically stable state. Well, the authour argues of telomeric proteins like TRF1 and TRF2 to *hold* the overhand and thus provide the stability :?:

Post Reply

Who is online

Users browsing this forum: No registered users and 4 guests