Sequence discrimination of the Zα domain of human ADAR1 during B–Z transition of DNA duplexes

Abstract

Edited by Gianni Cesareni

The Zβ domain of human DAI binds to Z-DNA via a novel B-Z transition pathway

“…Recently, NMR studies of complexes between hZa ADAR1 and non-CG-repeat DNA duplexes have shown that the k ex values for the B-form imino protons of the d(CACGTG) 2 and d(CGTACG) 2 are significantly altered by complex formation with hZa ADAR1 (Fig. 4B) [22]. This result strongly suggests that the BP complex also exists as intermediate structure during the B-Z transition of DNA duplexes that is induced by hZa ADAR1 .…”

The Zα domain of fish PKZ facilitates the B–Z conformational transition of oligonucleotide DNAs with d(GC)<italic><sub>n</sub></italic> inserts

“…The sequences were the substitute for d(CG) 6 and often used for discussion on the manner of interaction between Za and Z-DNA [31,32]. The sequence (CACGTG) 2 , (CGTACG) 2 , or (CGGCCG) 2 can co-crystallize with human Za ADAR1 , respectively [31], so Ha et al [31] considered hZa ADAR1 recognized Z-DNA in a conformation-specific manner, but not in a sequencespecific manner.…”

“…The non-(GC) repeat sequences were more difficult to form Z-DNA than d(CG) repeat sequences. Because non-(GC) repeat sequences had very low-binding affinity for Za ADAR1 than alternating d(CG) DNA, Seo et al [32] considered the possibility of flipping B-DNA into Z-DNA for non-(GC) repeat sequences was far below than alternating d(CG) DNA duplex.…”

NMR Study on the Preferential Binding of the Zα Domain of Human ADAR1 to CG-repeat DNA Duplex

“…The apparent relaxation rate constant of water (R 1w ) was determined by selective inversion recovery experiment using a DANTE sequence for selective water inversion. [12][13][14] The hydrogen exchange rate constants of the imino protons (k ex ) were measured by a water magnetization transfer, where a selective 180 o pulse for water was applied, followed by a variable delay, and then a 3-9-19 acquisition pulse was used to suppress the water signal. 12 The intensities of each imino proton were measured with 20 different delay times ranging from 5 to 100 ms.…”