Difference between revisions of "Part:BBa K2559000"

Latest revision as of 09:04, 16 October 2018

Bacterial cellulose synthase Z (BcsZ)

The BBa_K2559000 encodes an endoglucanase (Bcs Z) that is responsible for the hydrolysis of cellulose. Its roles in cellulose biosynthesis still remained obscure.

Usage and Biology

Bacterial cellulose synthase Z (BcsZ) in different bacteria species had been shown to function similarly to an endo-β-1,4-glucanase (cellulase). Nevertheless, BcsZ found in E. coli was even crystallized in a complex with the substrate cellopentaose. Its roles in cellulose biosynthesis still remain obscure. We suspect that the BcsZ and BlgX may responsible for the formation of the correct cellulose configuration through selective digestion.[1]

Figure 1 BcsZ adopts an (α/α)6-barrel fold. [2]

Degradation of CMC by BcsZ

The BcsZ in E. coli was even crystallized in a complex with the substrate cellopentaose. When BcsZ-overexpressing E. coli cells were grown on agar plates containing 2% CMC, a clear halo appeared around the colonies after staining with Congo Red. Purified cellulase from Aspergillus niger (Tokyo Chemical Industry, GenBank entry CAA03658.1) and bovine serum albumin served as positive and negative controls, respectively.[2]

Figure 2 The right area show degradation of CMC by BcsZ which indicated the cellulase activity of BcsZ in E.coli.[2]

We introduced bcsZ, H, A, B, C, D, bglX from the Acetobacter xylinum which are involved in the process of bacterial cellulose synthesis into the cyanobacteria.

Transgenic cyanobacteria with bcsZH-ABCD-bglX genes and the cellulose measurement

Measurement of cyanobacteria glucose (3 repeats). The same of amount of transgenic cyanobacteria with bcsZH-ABCD-bglX genes and wild-type were treated with lysozyme to break the cells. Due to lacking a direct way to measure the content of cellu;ose in bacterial cell wall. Therefore, glucose can be used as an alternative parameter for measuring the content of cellulose since it can be digested into glucose by cellulose. The differences between the red colum and blue column indicated that the content of bacteria cellulose.

Figure 3 The measurement of cellulose content in transgenic cyanobacteria which expressed bcs gene . The P-value verified that the distinction between treatment group  and control group.

The part is facilitate the in-depth research for other teams!

Reference :

1.Romling U & Galperin MY (Bacterial cellulose biosynthesis: diversity of operons, subunits, products, and functions. (Translated from eng) Trends Microbiol 23(9):545-557 (in eng).

2.Mazur O & Zimmer J (Apo- and cellopentaose-bound structures of the bacterial cellulose synthase subunit BcsZ. (Translated from eng) J Biol Chem 286(20):17601-17606 (in eng).

Sequence and Features