Exons: 25 PER3 has 19 transcripts (splice variants). Protein structure The PER3 protein has been identified to have the following features: Size: 1201 amino acids Molecular mass: 131888 Da Quaternary structure: Homodimer Post translational modifications The following are some known post transcriptional modifications to the Per3 gene: Phosphorylation by CSNK1E is weak and appears to require association with PER1 and translocation to the nucleus. Ubiquitinated. Modification sites at PhosphoSitePlus Modification sites at neXtProt References External links Transcription factors Circadian rhythm PAS-domain-containing proteins