Crystal structure of hypothetical protein HP0062 (O24902_HELPY) from Helicobacter pylori at 1.65 A resolution.

The HP0062 gene encodes a small acidic protein of 86 amino acids with a theoretical pI of 4.6. The crystal structure of hypothetical protein HP0062 from Helicobacter pylori has been determined at 1.65 A by molecular-replacement method. The crystallographic asymmetric unit contains dimer, in which HP0062 monomer folds into a helix-hairpin-helix structure. The two protomers are primarily held together by extensive hydrophobic interactions in an antiparallel arrangement, forming a four helix bundle. Aromatic residues located at a or g position in the heptad leucine zipper are not major contributor required for HP0062 dimerization but important for the thermostability of this protein.