The gene encoding the ribulose monophosphate pathway enzyme, 3-hexulose-6-phosphate synthase, from Aminomonas aminovorus C2A1 is adjacent to coding sequences that exhibit similarity to histidine biosynthesis enzymes.

In an attempt to understand better the organisation of genes encoding enzymes of the ribulose monophosphate pathway (RuMP), the 3-hexulose 6-phosphate synthase gene (hps) and flanking sequences were cloned from the obligate methylotroph Aminomonas aminovorus C2A1. To date only three hps containing gene clusters from methylotrophs have been characterised and these contain genes encoding other RuMP enzymes. However, hps from A. aminovorus C2A1 was shown to be adjacent to coding sequences for products with sequence similarity to histidine biosynthesis enzymes. Furthermore, none of the hps homologue containing gene clusters, from genome sequences previously analysed or analysed in this paper, were similar in organisation to that of A. aminovorus C2A1.