The present invention relates to the provision of a DNA sequence of the major grass pollen allergen Lol p 4. The invention also encompasses fragments, new combinations of partial sequences and point mutants having a hypoallergenic action. The recombinant DNA molecules and the derived polypeptides, fragments, new combinations of partial sequences and variants can be utilized for the therapy of pollen-allergic diseases. The proteins prepared by recombinant methods can be employed for in vitro and in vivo diagnosis of pollen allergies.