This family includes domains distantly related to lipocalins. However, they do contain the important GXW motif in the first strand. The protein in this family include aln5 Swiss:B6SEG2 which is involved in biosynthesis of alnumycin [1]. The family also includes the ZFK protein from Trypanosoma brucei which is a protein kinase. This domain is at the C-terminus of that protein [2]. The domain is also found as the C-terminal domain in StiJ a protein involved in producing stigmatellin. This domain has been assumed to catalyse a final cyclisation reaction [3].

1: Characterization of the alnumycin gene cluster reveals unusual gene products for pyran ring formation and dioxan biosynthesis. Oja T, Palmu K, Lehmussola H, Lepparanta O, Hannikainen K, Niemi J, Mantsala P, Metsa-Ketela M; Chem Biol. 2008;15:1046-1057. PMID:18940666

2: Deletion of a novel protein kinase with PX and FYVE-related domains increases the rate of differentiation of Trypanosoma brucei. Vassella E, Kramer R, Turner CM, Wankell M, Modes C, van den Bogaard M, Boshart M; Mol Microbiol. 2001;41:33-46. PMID:11454198

3: The biosynthesis of the aromatic myxobacterial electron transport inhibitor stigmatellin is directed by a novel type of modular polyketide synthase. Gaitatzis N, Silakowski B, Kunze B, Nordsiek G, Blocker H, Hofle G, Muller R; J Biol Chem. 2002;277:13082-13090. PMID:11809757