Part:BBa_K4689060

Ribulose bisphosphate carboxylase assembly chaperone (rbcX)

RbcX is a chaperone protein that plays a crucial role in assisting the correct assembly and stability of RuBisCO, particularly in the formation of RuBisCO holoenzymes. It is often found in association with RuBisCO and is involved in the biogenesis and maintenance of this critical enzyme complex.

Significance as a Chaperone:

The significance of RbcX as a chaperone in the context of RuBisCO is multifaceted:

1. Proper Assembly: RuBisCO is a complex enzyme composed of large and small subunits. The assembly of these subunits into a functional enzyme is intricate and sensitive to environmental conditions. RbcX assists in the correct assembly of RuBisCO, ensuring that the large and small subunits come together in the appropriate manner to form an active enzyme.

2. Prevention of Misfolding: Chaperone proteins like RbcX help prevent misfolding or aggregation of the subunits during their synthesis or transport to the chloroplast, where RuBisCO is primarily located. Misfolded or aggregated subunits can lead to the degradation of non-functional protein and a decrease in photosynthetic efficiency.

3. Stability Enhancement: RbcX also aids in stabilizing the RuBisCO complex. It helps protect the assembled enzyme from denaturation or breakdown in response to various stress factors, such as high temperatures or oxidative stress, which are common challenges faced by photosynthetic organisms.

4. Chaperoning During Stress: In conditions of environmental stress, such as heat or drought, the role of chaperones like RbcX becomes especially critical. They assist RuBisCO in maintaining its structure and activity, allowing photosynthesis to continue even under adverse conditions.

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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
  INCOMPATIBLE WITH RFC[1000]

  Illegal BsaI.rc site found at 385
  

REFERENCES :

1.Saschenbrecker, S., Bracher, A., Rao, K. V., Rao, B. V., Hartl, F. U., & Hayer-Hartl, M. (2007). Structure and function of RbcX, an assembly chaperone for hexadecameric Rubisco. Cell, 129(6), 1189-1200.

2.Onizuka, T., Endo, S., Akiyama, H., Kanai, S., Hirano, M., Yokota, A., ... & Miyasaka, H. (2004). The rbcX gene product promotes the production and assembly of ribulose-1, 5-bisphosphate carboxylase/oxygenase of Synechococcus sp. PCC7002 in Escherichia coli. Plant and cell physiology, 45(10), 1390-1395.