Z-Hunt
From Christoph's Personal Wiki
Z-Hunt (aka ZHunt) is an algorithm for predicting the propensity of DNA to flip from the B-form to the Z-form. The original algorithm was written by Dr. P. Shing Ho in 1986[1] and was later developed by Tracy Camp, P. Christoph Champ, Sandor Maurice, and Jeffrey M. Vargason for genome-wide mapping of Z-DNA (with P. Shing Ho as the principal investigator)[2]. Z-Hunt is available for use Online at ZHunt Online.
Z-score
Note: The following table is a list of test sequences with their corresponding conformational assignments and Z-scores. This "Z-score" should not be confused with the statistical "Standard score". Here, it describes the propensity of a given sequence to adopt the left-handed form of DNA; it is simply a probability score.
Sequence/conf. assignments | Z-score
----------------------------|------------
CGCGCGCGCGCGCGCGCGCGCGCG | 2 x 10e+11
ASASASASASASASASASASASAS |
|
CGCGCGCGCGCG | 4 x 10e+07
ASASASASASAS |
|
CACACACACACACACACACACACA | 2 x 10e+05
ASASASASASASASASASASASAS |
|
CACACACACACA | 2 x 10e+04
ASASASASASAS |
|
CGCGCGCGCGCG GCGCGCGCGCGC | 2 x 10e+08
ASASASASASAS SASASASASASA |
|
CGCGCG GCGCGC CGCGCG GCGCGC | 7 x 10e+04
ASASAS SASASA ASASAS SASASA |
|
* * * * * * |
CCCGCCCGCCCGCCCGCCCGCCCG | 8 x 10e+04
ASASASASASASASASASASASAS |
|
* * * * * * |
CAGGCAGGCAGGCAGGCAGGCAGG | 1 x 10e+03
ASASASASASASASASASASASAS |
|
* * * * * * * * * * * * |
CCCCCCCCCCCCCCCCCCCCCCCC | 52
ASASASASASASASASASASASAS |
|
ATATATATATATATATATATATAT | 38
SASASASASASASASASASASASA |
|
AAAAAAAAAAAAAAAAAAAAAAAA | 3 x 10e-07
ASASASASASASASASASASASAS |
|
| Various test sequences are shown with their corresponding Z-score as assigned by Z-hunt [version 1]. Z-scores are defined as the number of random base pairs that must be scanned, on average, to find a sequence with equal or better Z-forming capacity relative to the sequence in question. The conformation selected by Z-hunt for each nucleotide (A for anti and S for syn) are indicated below each sequence. Bases which deviate from perfect purine-pyrimidine alternation are designated by dots above that nucleotide. Discontinuities in the conformational phases produced by Z-Z junctions are represented by gaps separating the sequence.[1] |
See also
- Z-DNA
- wikipedia:DNA supercoil
- wikipedia:Gibbs free energy
- wikipedia:Topoisomerase
- wikipedia:Linking number
- wikipedia:Möbius strip
References
- ↑ 1.0 1.1 Ho PS, Ellison MJ, Quigley GJ, Rich A (1986). A computer aided thermodynamic approach for predicting the formation of Z-DNA in naturally occurring sequences. EMBO J, 5(10):2737-2744.
- ↑ Champ PC, Maurice S, Vargason JM, Camp T, Ho PS (2004). Distributions of Z-DNA and nuclear factor I in human chromosome 22: a model for coupled transcriptional regulation. Nucleic Acids Research, 32(22):6501-6510.
Further reading
- Ho PS (1994). The non-B-DNA structure of d(CA/TG)n does not differ from that of Z-DNA. Proc Natl Acad Sci USA, 91(20):9549-9553.
- Schroth GP, Chou PJ, Ho PS (1992). Mapping Z-DNA in the human genome. Computer-aided mapping reveals a nonrandom distribution of potential Z-DNA-forming sequences in human genes. J Biol Chem, 267(17):11846-55.
External links
- ZHunt Online Server — front end by Sandor Maurice; back end by Sandor Maurice and P. Christoph Champ.
- make-na server — create custom DNA structures (in PDB format)
