Novel polypeptide-modifying enzymes and uses thereof

A nucleic acid, comprising a nucleic acid sequence selected from the group consisting of:

• (i) a nucleic acid of any one of SEQ ID NOs:
• 1 (aerC), 3 (aerD), 5 (aerF), or 7 (aerE);
• (ii) a nucleic acid sequence of at least 80 or 90% sequence identity with a nucleic acid sequence of (i);
• (iii) a nucleic acid sequence that hybridizes to a nucleic acid sequence of (i) or (ii) under stringent conditions;
• (iv) a fragment of any of the nucleic acid sequences of (i) to (iii), that hybridizes to a nucleic acid sequence of (i) or (ii) under stringent conditions;
• (v) a nucleic acid sequence degenerated with respect to a nucleic acid sequence of any of (i) to (iv);
• (vi) a nucleic acid sequence, wherein said nucleic acid sequence is derivable by substitution, addition and/or deletion of at least one nucleic acid of the nucleic acid sequences of (i) to (v) that hybridizes to a nucleic acid sequence of (i) or (ii) under stringent conditions;
• (vii) a nucleic acid sequence complementary to the nucleic acid sequence of any of (i) to (vi);
• wherein the nucleic acid sequence of any of (i) to (vii),
• (a) when based on SEQ ID NO:
• 1 (aerC) encodes a polypeptide that has cobalamin-dependent rSAM methyltransferase activity;
• (b) when based on SEQ ID NO:
• 3 (aerD) encodes a polypeptide that has rSAM epimerase activity to convert one or more L-amino acid(s) into D-amino acid(s);
• (c) when based on SEQ ID NO:
• 5 (aerF) encodes a polypeptide that has dehydratase activity to dehydrate an N-terminal threonine or serine to an alpha-keto functional group;
• or
• (d) when based on SEQ ID NO:
• 7 (aerE) and encodes a polypeptide that has asparagine (ASN)N-methyltransferase activity for methylating one or more side chain amines of one or more asparagine(s).