This old version of Proteopedia is provided for student assignments while the new version is undergoing repairs. Content and edits done in this old version of Proteopedia after March 1, 2026 will eventually be lost when it is retired in about June of 2026.
Apply for new accounts at the new Proteopedia. Your logins will work in both the old and new versions.
225d
From Proteopedia
| Line 1: | Line 1: | ||
[[Image:225d.jpg|left|200px]] | [[Image:225d.jpg|left|200px]] | ||
| - | + | <!-- | |
| - | + | The line below this paragraph, containing "STRUCTURE_225d", creates the "Structure Box" on the page. | |
| - | + | You may change the PDB parameter (which sets the PDB file loaded into the applet) | |
| - | + | or the SCENE parameter (which sets the initial scene displayed when the page is loaded), | |
| - | | | + | or leave the SCENE parameter empty for the default display. |
| - | | | + | --> |
| - | + | {{STRUCTURE_225d| PDB=225d | SCENE= }} | |
| - | + | ||
| - | + | ||
| - | }} | + | |
'''A TETRAMERIC DNA STRUCTURE WITH PROTONATED CYTOSINE:CYTOSINE BASE PAIRS''' | '''A TETRAMERIC DNA STRUCTURE WITH PROTONATED CYTOSINE:CYTOSINE BASE PAIRS''' | ||
| Line 19: | Line 16: | ||
==About this Structure== | ==About this Structure== | ||
| - | + | Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=225D OCA]. | |
==Reference== | ==Reference== | ||
A tetrameric DNA structure with protonated cytosine.cytosine base pairs., Gehring K, Leroy JL, Gueron M, Nature. 1993 Jun 10;363(6429):561-5. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/8389423 8389423] | A tetrameric DNA structure with protonated cytosine.cytosine base pairs., Gehring K, Leroy JL, Gueron M, Nature. 1993 Jun 10;363(6429):561-5. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/8389423 8389423] | ||
| - | [[Category: Protein complex]] | ||
[[Category: Gehring, K.]] | [[Category: Gehring, K.]] | ||
[[Category: Gueron, M.]] | [[Category: Gueron, M.]] | ||
[[Category: Leroy, J L.]] | [[Category: Leroy, J L.]] | ||
| - | [[Category: | + | [[Category: Dna]] |
| - | [[Category: | + | [[Category: Intercalated cytosine tetrad]] |
| - | [[Category: | + | [[Category: Nmr]] |
| - | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sat May 3 18:20:13 2008'' | |
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | |
Revision as of 15:20, 3 May 2008
A TETRAMERIC DNA STRUCTURE WITH PROTONATED CYTOSINE:CYTOSINE BASE PAIRS
Overview
Oligomers containing tracts of cytidine form hemiprotonated base pairs at acid pH and have been considered to be double-stranded. We have solved the structure of the DNA oligomer 5'-d(TCCCCC) at acid pH and find that it is a four-stranded complex in which two base-paired parallel-stranded duplexes are intimately associated, with their base pairs fully intercalated. The relative orientation of the duplexes is antiparallel, so that each base pair is face-to-face with its neighbours. The NMR spectrum displays only six spin systems, showing that the structure is highly symmetrical on the NMR timescale; the four strands are equivalent. A model derived by energy minimization and constrained molecular dynamics shows excellent compatibility with the observed nuclear Overhauser effects (NOEs) particularly for the very unusual inter-residue sugar-sugar NOEs H1'-H1', H1'-H2" and H1'-H4'. These NOEs are probably diagnostic for such tetrameric structures.
About this Structure
Full crystallographic information is available from OCA.
Reference
A tetrameric DNA structure with protonated cytosine.cytosine base pairs., Gehring K, Leroy JL, Gueron M, Nature. 1993 Jun 10;363(6429):561-5. PMID:8389423 Page seeded by OCA on Sat May 3 18:20:13 2008
