# DNA and Persistence length

1. Mar 19, 2006

### karthik3k

The persistence length of a double stranded DNA is reported to be ~ 150 bp.

If so how can DNA of ~100 bp and less bend or circularize?

Or is the definition of persistence length wrong ?

2. Mar 20, 2006

### pattylou

What is the definition of persistence length?

The ORI is pretty long itself, so I'd suspect 100 bp would be too short.

3. Mar 20, 2006

### karthik3k

whats ORI ?

4. Mar 21, 2006

### pattylou

What's the definition of persistence length?

The ori is the origin of replication. I have no idea if it's relevant to the topic, because I'm not sure what "persistence length" means.

5. Mar 21, 2006

### Monique

Staff Emeritus
from the net:
Or: the length of the DNA along which a thermally excited bend of 1 radian typically occurs (the DNA is essentially straight over shorter distances). Since the persistance length is based on just thermal fluxuations, it should be possible to bend it further with binding energies for instance (wrapping DNA around histones).