Cloning of complementary DNA encoding the pB1 component of the 54-kilodalton glycoprotein of boar seminal plasma

Complementary DNA (cDNA) encoding a protein component pB1 (also pAIF-1 and DQH) of the 54-kilodalton glycoprotein of boar seminal plasma was cloned an d its nucleotide sequence was determined (Gene Bank accession no. AF047026) . The pB1 precursor protein is a 130-amino-acid-long polypeptide containing a 25-amino-acid-long signal peptide. The amino acid sequence of the pB1 is homologous to that of SFP1-BOVIN (named also BSP-A(1)/A(2), PDC-109/major protein and SVSpl09), SFP3_BOVIN (BSP-A(3)), SFP4_ BOVIN (BSP30 KD), and SP 1_HORSE (HSP-1) seminal plasma proteins. The homology extends also for the signal peptide of SFP1_BOVIN protein. All these seminal plasma proteins con tain two fibronectin type-ii domains that differ from those found in other proteins such as colagenases, fibronectins, and mannose receptors. The firs t domain located in the N-terminal region of pB1 is four amino acids shorte r than those present in other proteins. High homology is also observed betw een 3' noncoding regions of the nucleotide sequences of cDNAs of pB1_PIG an d SFP1_BOVIN (Gene Bank accession nos. AF047026 and P02784, respectively). Mel. Reprod. Dev. 52:303-309, 1999. (C) 1999 Wiley-Liss, Inc.