There is provided inter alia an isolated polynucleotide, wherein the polynucleotide encodes a polypeptide selected from the group consisting of: (a) a polypeptide having the amino acid sequence according to SEQ ID NO: 1, (b) a functional derivative of a polypeptide having the amino acid sequence according to SEQ ID NO: 1, wherein the functional derivative has an amino acid sequence which is at least 80% identical over its entire length to the amino acid sequence of SEQ ID NO: 1, and (c) a polyThere is provided inter alia an isolated polynucleotide, wherein the polynucleotide encodes a polypeptide selected from the group consisting of: (a) a polypeptide having the amino acid sequence according to SEQ ID NO: 1, (b) a functional derivative of a polypeptide having the amino acid sequence according to SEQ ID NO: 1, wherein the functional derivative has an amino acid sequence which is at least 80% identical over its entire length to the amino acid sequence of SEQ ID NO: 1, and (c) a polypeptide having the amino acid sequence according to SEQ ID NO: 3.peptide having the amino acid sequence according to SEQ ID NO: 3.
