Synthesis of a small, cysteine-rich, 29 amino acids long peptide inMycoplasma pneumoniae

A 205-210 bases long, small RNA (MP200RNA) of Mycoplasma pneumoniae encodes an open reading frame (ORF pmp200) that has the potential to be translated into a 29 amino acids long peptide with nine cysteines. The expression of this peptide in M. pneumoniae was proven indirectly by constructing a gene fusion between the ORF pmp200 and mrfp1, the gene encoding the monomeric red fluorescent protein. The fusion construct was translated in M. pneumoniae. The corresponding fusion protein, with a molecular mass of approximately 35,000 Da, was isolated and the correct sequence was proven by Edman degradation and by mass spectrometry.