Structure of the tetradecanucleotide d(CCCCGGTACCGGGG)2 as an A-DNA duplex.

ABSTRACT: The crystal structure of the tetradecanucleotide sequence d(CCCCGGTACCGGGG)(2) has been determined at 2.5 Å resolution in the tetragonal space group P4(1). This sequence was designed with the expectation of a four-way junction. However, the sequence crystallized as an A-DNA duplex and represents more than one full turn of the A-helix. The crystallographic asymmetric unit consists of one tetradecanucleotide duplex. The structural parameters of the A-type DNA duplex structure and the crystal-packing arrangement are described. One Mn(2+) ion was identified with direct coordination to the N7 position of G(13) and a water molecule at the major-groove side of the C(2)·G(13) base pair.

SUBMITTER: Mandal PK 

PROVIDER: S-EPMC3325805 | biostudies-literature | 2012 Apr

REPOSITORIES: biostudies-literature