5C98

1.45A resolution structure of SRPN18 from Anopheles gambiae

Summary for 5C98

• Entry DOI: 10.2210/pdb5c98/pdb
• Descriptor: AGAP007691-PB (2 entities in total)
• Functional Keywords: serpin, serine protease, insect immunity, enzyme inhibitor, unknown function
• Biological source: Anopheles gambiae (African malaria mosquito)
• Total number of polymer chains: 2
• Total formula weight: 86357.48

Authors

Lovell, S.,Battaile, K.P.,Gulley, M.,Zhang, X.,Meekins, D.A.,Gao, F.P.,Michel, K. (deposition date: 2015-06-26, release date: 2016-09-14, Last modification date: 2023-09-27)

Primary citation

Meekins, D.A.,Zhang, X.,Battaile, K.P.,Lovell, S.,Michel, K.
1.45 angstrom resolution structure of SRPN18 from the malaria vector Anopheles gambiae.
Acta Crystallogr F Struct Biol Commun, 72:853-862, 2016

PubMed Abstract: Serine protease inhibitors (serpins) in insects function within development, wound healing and immunity. The genome of the African malaria vector, Anopheles gambiae, encodes 23 distinct serpin proteins, several of which are implicated in disease-relevant physiological responses. A. gambiae serpin 18 (SRPN18) was previously categorized as non-inhibitory based on the sequence of its reactive-center loop (RCL), a region responsible for targeting and initiating protease inhibition. The crystal structure of A. gambiae SRPN18 was determined to a resolution of 1.45 Å, including nearly the entire RCL in one of the two molecules in the asymmetric unit. The structure reveals that the SRPN18 RCL is extremely short and constricted, a feature associated with noncanonical inhibitors or non-inhibitory serpin superfamily members. Furthermore, the SRPN18 RCL does not contain a suitable protease target site and contains a large number of prolines. The SRPN18 structure therefore reveals a unique RCL architecture among the highly conserved serpin fold.

PubMed: 27917832
DOI: 10.1107/S2053230X16017854

Experimental method

X-RAY DIFFRACTION (1.45 Å)