3WQB

Crystal structure of aeromonas sobria serine protease (ASP) and the chaperone (ORF2) complex

Summary for 3WQB

• Entry DOI: 10.2210/pdb3wqb/pdb
• Related: 2MK4 2OXA
• Descriptor: Extracellular serine protease, Open reading frame 2, CALCIUM ION, ... (4 entities in total)
• Functional Keywords: asp, serine protease; orf2, chaperone, calcium binding, extracellular space, hydrolase-chaperone complex, hydrolase/chaperone
• Biological source: Aeromonas sobria; More
• Total number of polymer chains: 2
• Total formula weight: 80110.88

Authors

Kobayashi, H.,Yoshida, T.,Miyakawa, T.,Kato, R.,Tashiro, M.,Yamanaka, H.,Tanokura, M.,Tsuge, H. (deposition date: 2014-01-24, release date: 2015-03-25, Last modification date: 2023-11-08)

Primary citation

Kobayashi, H.,Yoshida, T.,Miyakawa, T.,Tashiro, M.,Okamoto, K.,Yamanaka, H.,Tanokura, M.,Tsuge, H.
Structural Basis for Action of the External Chaperone for a Propeptide-deficient Serine Protease from Aeromonas sobria.
J.Biol.Chem., 290:11130-11143, 2015

PubMed Abstract: Subtilisin-like proteases are broadly expressed in organisms ranging from bacteria to mammals. During maturation of these enzymes, N-terminal propeptides function as intramolecular chaperones, assisting the folding of their catalytic domains. However, we have identified an exceptional case, the serine protease from Aeromonas sobria (ASP), that lacks a propeptide. Instead, ORF2, a protein encoded just downstream of asp, appears essential for proper ASP folding. The mechanism by which ORF2 functions remains an open question, because it shares no sequence homology with any known intramolecular propeptide or other protein. Here we report the crystal structure of the ORF2-ASP complex and the solution structure of free ORF2. ORF2 consists of three regions: an N-terminal extension, a central body, and a C-terminal tail. Together, the structure of the central body and the C-terminal tail is similar to that of the intramolecular propeptide. The N-terminal extension, which is not seen in other subtilisin-like enzymes, is intrinsically disordered but forms some degree of secondary structure upon binding ASP. We also show that C-terminal (ΔC1 and ΔC5) or N-terminal (ΔN43 and ΔN64) deletion eliminates the ability of ORF2 to function as a chaperone. Characterization of the maturation of ASP with ORF2 showed that folding occurs in the periplasmic space and is followed by translocation into extracellular space and dissociation from ORF2, generating active ASP. Finally, a PSI-BLAST search revealed that operons encoding subtilases and their external chaperones are widely distributed among Gram-negative bacteria, suggesting that ASP and its homologs form a novel family of subtilases having an external chaperone.

PubMed: 25784551
DOI: 10.1074/jbc.M114.622852

Experimental method

X-RAY DIFFRACTION (1.41 Å)