Background and Technology

To overcome the limitations of protein expression in Streptomyces, we successfully introduced a high-expression system derived from Rhodococcus into Streptomyces hosts. The expression system in Rhodococcus is industrially validated, exhibiting robust transcriptional activity sufficient to produce low-cost commodity chemicals such as acrylamide.
Specifically, we introduced the transcriptional regulators NhhC and NhhD, along with the N-Hase promoter from the Rhodococcus nitrile hydratase gene cluster, into Streptomyces lividans. This demonstrated that the Rhodococcus-based system functions in Streptomyces, leading to the development of a high-expression vector, pHSA81.
To further enable efficient extracellular secretion, we incorporated Tat secretion signal sequences from S. avermitilis and modified the vector to replicate in E. coli, resulting in the construction of a shuttle vector, pEHSA81k-ss1, optimized for use in Streptomyces. Secretion efficiency was evaluated and confirmed. Additionally, we developed seven other expression vectors containing alternative Tat signal peptides (besides pEHSA81k-ss1), enabling flexible adaptation depending on the target protein.

Data

- Successful expression and secretion demonstrated for enzymes such as Pullulanase, Esterase, Chitinase, Phospholipase A2, and Amylase.
- In some cases, the target protein accounted for over two-thirds of the total secreted proteins in the culture supernatant.

Patent

JPB 006906215

Researcher

Dr. Michihiko Kobayashi (University of Tsukuba)

Expectations

We are seeking partners interested in adopting this expression vector system for protein production. Material Transfer Agreements (MTA) for technical evaluation are available.
Project ID:WL-05177