The cosmid library from the strain of pristinamycin-producing Streptomyces pristinaespiralis F618 was screened using a probe of partial Afsk-like gene that involved in pristinamycin biosynthsis, and an approximate 8 kb DNA fragment was obtained. The nucleotide sequence analysis indicated that a 1146 bp DNA fragment contained one complete open reading frame (ORF) coding for Spr1.The predicted protein was homologous to glutamine synthetase as shown by the Blastp program.To investigate the function of Spr1 gene (HQ450023), we have isolated the Spr1 mutants，and then the fermentation culture of mutants and S.pristinaespiralis F618 were examined by HPLC. A positive correlation between the product of Spr1 gene and the pristinamycin biosynthesis was observed.