Combining protein and metabolic engineering to construct efficient microbial cell factories.

Microbial cell factories offer great opportunities for the feasible biosynthesis of various value-added products from renewable resources. In recent years, protein engineering has served as a powerful approach for generating enzymes or proteins with desirable properties. As an effective toolbox, many efforts have been employed into protein engineering for the improvement of biological networks by enhancing, regulating, expanding, and innovating metabolic pathways. In combination with traditional metabolic engineering strategies, protein engineering has demonstrated tremendous promise in facilitating the production of many bio-based products. In this review, we present recent trends and strategies available for protein engineering, and highlight the successful interplay between protein and metabolic engineering in boosting the production of target compounds using diverse microbial cell factories. The perspectives for protein design in metabolic engineering are also briefly discussed.