Protein domain repetition is enriched in Streptococcal cell-surface proteins

► Association between tandem protein domain and subcellular localization was examined. ► Proteins that have no tandem repeats are significantly enriched in cytoplasm. ► Proteins with repeats are significantly enriched in extracytoplasmic locations. ► Proteins containing high domain repeats are mostly virulence-associated. ► Variation in the number of repeats bring about subtle or drastic structural changes.