A novel gene has been characterized, designated C16orf5, with an unusually high content of proline residues (40% over 104 residues) at the N-terminus of the protein. The C-terminus of the protein is also cysteine rich with 14 cysteine residues present. Analysis using Northern and dot blots showed that the highest expression of this gene is in the brain. The gene was located on chromosome 16 at band p13.3 by FISH to metaphase chromosomes. Southern blot analysis with a human-rodent somatic cell hybrid panel showed a location between the somatic hybrid breakpoints 23HA and CY196. This gene comprises at least four exons and an open reading frame of 786 bp encoding a predicted protein of 261 amino acids. Analysis of this protein using PSORTII predicted a nuclear localization.