Methanol produced from coal is a key raw material in coal-rich China. A team around SUN Jibing at CAS Tianjin Institute of Industrial Biotechnology constructed fusion proteins of ribulose monophosphate pathway enzymes. The fusion engineering strategy enhanced methanol bioconversion to fructose 6-phosphate (F6P), an important metabolic intermediate. NAD-dependent methanol dehydrogenase (Mdh), 3-hexulose-6-phosphate synthase (Hps) and 6-phospho-3-hexuloisomerase (Phi) from different sources were evaluated for their catalytic activities. The candidates with the highest activity were then used to construct difunctional fusion proteins (Mdh-Hps and Hps-Phi) and trifunctional fusion proteins (Mdh-Hps-Phi) with flexible linkers. Effects of linker length on the catalytic efficiency of fusion proteins were also investigated. The best fusion protein showed 4.8-fold improvement in methanol oxidation efficiency and 30% improvement in F6P formation efficiency.

CAS news release, October 15, 2018