Latent periodicity regions in amino acid sequences

We a propose mathematical approach to searching for latent periodicity in a mino acid sequences. The statistical significance of the latent periodicity was evaluated by the Monte Carlo method. Search for latent periodicity in the SWISS-PROT bank sequences reveals over 10% proteins with latent periodi city including enzymes. We present amino acid sequences with latent periodi city revealed in lipoamide dehydrogenase (DLDH_AZOVI), asparagine synthase (ASN1_YEAST), endochitinase 2 (CHI2_COCIM), and Rho/Rac effector (CTRO_MOUS E). These proteins feature latent periodicity regions 19, 6, 11, and 7 amin o acid long, respectively. The possible functional and evolutionary signifi cance of the latent periodicity regions is discussed.