Crystallographic analysis of an RNA polymerase ?-subunit fragment complexed with -10 promoter element ssDNA: quadruplex formation as a possible tool for engineering crystal contacts in protein-ssDNA complexes.

ABSTRACT: Structural studies of -10 promoter element recognition by domain 2 of the RNA polymerase ? subunit [Feklistov & Darst (2011), Cell, 147, 1257-1269] reveal an unusual crystal-packing arrangement dominated by G-quartets. The 3'-terminal GGG motif of the oligonucleotide used in crystallization participates in G-quadruplex formation with GGG motifs from symmetry-related complexes. Stacking between neighboring G-quadruplexes results in the formation of pseudo-continuous four-stranded columns running throughout the length of the crystal (G-columns). Here, a new crystal form is presented with a different arrangement of G-columns and it is proposed that the fortuitous finding of G-quartet packing could be useful in engineering crystal contacts in protein-ssDNA complexes.

SUBMITTER: Feklistov A 

PROVIDER: S-EPMC3758139 | biostudies-literature | 2013 Sep

REPOSITORIES: biostudies-literature