Part:BBa_K4382001

An endoglucanase, EG5C-1

It degrades cellulase

Usage and Biology

EG5C-1( GenBank: MG324233.1) is a truncated version of EG5C(a typical endoglucanase) lacking the CBM3 domain. EG5C-1 is a processive endoglucanase, i.e. a single enzyme can perform both endoglucanase and exoglucanase activity. This was confirmed by a different substrate preference and shown by the following observations:

EG5C-1 degrades endoglucanase almost as efficiently as EG5C (a typical endoglucanase) - which shows that it acts as an endoglucanase. Further assays were carried out using crystalline versions of cellulose i.e. Avicel and Filter paper. Degradation of these substrates indicate exoglucanase activity. EG5C-1 shows much more efficient exonuclease degradation than EG5C.

Processivity is an important property of this endo/exoglucanase - which is shown by an increase in yield of reducing sugar in EG5C-1 as opposed to EG5C. This is due to the missing carbohydrate binding domain which perhaps sterically hinders other enzymes from binding or disallowing smooth movement across the cellulose structure.

Due to the absence of CBM-3a, binding of EG5C-1 to the cellulose structure is much weaker than that of EG5C or EG5C-2. This is advantageous, as enzymes could be recycled again and again - thus potentially being advantageous for industrial applications.

Degradation of cello-oligosaccharides gave rise to cellobiose and cellotriose. Even cellotriose degradation gives rise to cellobiose; and no glucose was detected - thus indicating a transglycosylation reaction.

A consequence of this is that an association of this enzyme with a β-glucosidase is important to form glucose. This “synergy” or complementarity in function of two or more classes of enzymes which act differently on cellulose is commonly seen between different enzymes.

EG5C-1 can degrade both Carboxymethyl cellulose (CMC) as well as insoluble cellulosic substrates.

References

1. Wu, B., Zheng, S., Pedroso, M. M., Guddat, L. W., Chang, S., He, B., & Schenk, G. (2018, January 29). Processivity and enzymatic mechanism of a multifunctional family 5 endoglucanase from Bacillus subtilis BS-5 with potential applications in the saccharification of cellulosic substrates. Biotechnology for Biofuels, 11(1). https://doi.org/10.1186/s13068-018-1022-2

Sequence and Features

Assembly Compatibility:

• 10
  COMPATIBLE WITH RFC[10]
• 12
  COMPATIBLE WITH RFC[12]
• 21
  COMPATIBLE WITH RFC[21]
• 23
  COMPATIBLE WITH RFC[23]
• 25
  COMPATIBLE WITH RFC[25]
• 1000
  COMPATIBLE WITH RFC[1000]