I'd like to ask about the DNA set used for the analysis that is presented in Fig 5. in the NAR 2003 paper. Are those structures previously classified as A, B and TA DNA by other means (?) before doing the Zp and Zp(h) calculations to confirm their differences? Where can I look for the structures which were used? (I guess it is somewhere in reference 81, Patikoglou,G.A. et al (1999))
Thanks for asking about the DNA datasets used in Figure 5 of
the 3DNA 2003 NAR paper. Yes, the structures are previously assigned as A-, B- and TA-DNA by other means before we introduced Zp and Zp(h) to classify the three types of dinucleotide steps automatically. A- and B-DNA are based on conventional parameters (Slide/Roll, sugar puckers etc), as in the NDB, and the TA-DNA is mainly inspired by the work of Guzikevich‐Guerstein and Shakked (
ref. 80):
A detailed structural analysis of two early examples of the TATA‐box DNA bound to the TATA‐box binding protein (TBP) (10,79) led Guzikevich‐Guerstein and Shakked (80) to propose that the 8 bp TATA‐box adopts a novel TA‐DNA conformation, different from either A or B DNA. The structures of many more such complexes have since been determined (81) and, as shown in Table 2 and Figure 5, all TATA‐box regions share similar conformational features.
So the complete list was
not taken directly from somewhere in
ref. 81, but compiled specifically for the work. The actual structure list used in producing Figure 5 for the TA-DNA steps can be found in the thread "
DNA standards/statistics using 3DNA", dated August 2006. For A-DNA and B-DNA structures used in Figure 5 of the 2003 paper, I need to locate my original record from (nearly) a decade ago -- I will write a post about my findings on the 3DNA homepage, possibly by next week.
HTH,
Xiang-Jun