Autocatalytic subunit processing couples active site formation in the 20S proteasome to completion of assembly

Article Abstract:

The importance of the beta-type proteasome subunit Doa3 is determined in 20S proteasome function in yeast. It is found that replacement of the leading Doa3 sequence is not possible with the propeptide of another beta subunit. A trans function by the Doa3 propeptide enables the insertion of the mature Doa3 domain into the proteasome. Such observation implies the role of Doa3 as a subunit-specific chaperone during proteasome biogenesis. Further results also suggest the importance of the N-terminal threonine of Doa3 in the chymotrysin-type active sites of proteasome.

Physiological aspects, Yeast, Yeast (Food product), Binding sites (Biochemistry), Active sites (Biochemistry)

---

Coordinated dual cleavages induced by the proteasome regulator PA28 lead to dominant MHC ligands

Article Abstract:

The gamma-interferon inducible PA28 protein complex, or 11S regulator, which is composed of two homologous subunit forming a hexa- or heptameric ring structure, is known to associate with the 20S proteasome particle. The kinetics of product generation by 20S proteasomes with and without PA28 is studied. Results indicate that the PA28 regulator significantly alters the cleavage mechanism of the proteasome and optimizes the generation of dominant T cell epitopes.

Major histocompatibility complex, Ligands (Biochemistry), Scission (Chemistry)

---

Protein translocation channels in the proteasome and other proteases

Article Abstract:

Active site compartmentalization is another unique feature of cytoplasmic peptidases which features adenosine triphosphatase hydrolysis-assisted substrate unfolding. ATP hydrolysis directly provide the energy for translocation. Translocation in turn, commits the proteins to degradation resulting from hydrolysis of the substrate at the distal end of the selective channel.

Analysis, Proteins, Cell compartmentation

Similar abstracts:

• Abstracts: Crystal structure of the cys2 activator-binding domain of protein kinase C-delta in complex with phorbol ester
• Abstracts: Autotrophic ammonia-oxidizing bacteria contribute minimally to nitrification in a nitrogen-impacted forested ecosystem
• Abstracts: A greedy promoter controls malarial var-iations. Methylglyoxal comes of age. Salmonella's sensor for host defense molecules
• Abstracts: The bHLH protein PTF1-p48 is essential for the formation of the exocrine and the correct spatial organization of the endocrine pancreas
• Abstracts: Maturation of fast and slow motor units during synapse elimination in the rabbit soleus muscles. EphB2 regulates axonal growth at the midline in the developing auditory brainstem

This website is not affiliated with document authors or copyright owners. This page is provided for informational purposes only. Unintentional errors are possible.