15 mer peptides Amino acid length Streptococcus peptides Human peptides Name of
human proteins
Alleles
        SPNR DRB1*11:01,DRB1*03:01
VDVYIRNLRKKLDLD 22-37 RNLRKKLD RNLRKILD    
DVYIRNLRKKLDLDC          
VYIRNLRKKLDLDCI          
VVDVYIRNLRKKLDL          
YIRNLRKKLDLDCIV          
RVVDVYIRNLRKKLD          
EEGYHVILAKDGQEA 131-148 KDGQEA KDGQEA TOPAZ1 DRB5*01:01
EGYHVILAKDGQEAL          
AVDFTSYQARVKNEE 187-206  QARVKNEE QERVKNEE SA DRB5*01:01
VDFTSYQARVKNEEV          
DFTSYQARVKNEEVA          
FTSYQARVKNEEVAI          
Three overlapping peptides obtained from Streptococcal protein, DNA binding response regulator represent three different human sperm proteins. The first overlapping peptide with amino acid length spanning between 22 - 37 represents six 15-mer peptides homologous with human sperm protein namely Spermatid perinuclear RNA binding protein (SPNR); the second overlapping peptide with amino acid length spanning between 131 - 148 represents two 15-mer peptides homologous with human Testis- and ovary- specific PAZ domain - containing protein (TOPAZ1); and the third overlapping peptide with amino acid length spanning between 187 - 206 represents four 15-mer peptides homologous with human Sperm antigen protein (SA). The amino acid sequences obtained from the three DNA binding response regulator protein showing resemblance with the human sperm proteins are RNLRKKLD, KDGQEA and QARVKNEE. All the three overlapping peptides bind to HLA - DRB alleles with high binding affinity.
Table 1: Promiscuous DNA binding response regulator peptides interprets functional resemblance with human sperm proteins.