2JGS

Circular permutant of avidin

Summary for 2JGS

• Entry DOI: 10.2210/pdb2jgs/pdb
• Related: 1AVD 1AVE 1IJ8 1LDO 1LDQ 1LEL 1NQN 1RAV 1VYO 2A5B 2A5C 2A8G 2AVI 2C4I 2CAM
• Descriptor: CIRCULAR PERMUTANT OF AVIDIN, BIOTIN (3 entities in total)
• Functional Keywords: biotin-binding protein, glycoprotein
• Biological source: GALLUS GALLUS (CHICKEN)
• Total number of polymer chains: 4
• Total formula weight: 58213.66

Authors

Maatta, J.A.E.,Hytonen, V.P.,Airenne, T.T.,Niskanen, E.,Johnson, M.S.,Kulomaa, M.S.,Nordlund, H.R. (deposition date: 2007-02-14, release date: 2008-03-04, Last modification date: 2023-12-13)

Primary citation

Maatta, J.A.E.,Airenne, T.T.,Nordlund, H.R.,Janis, J.,Paldanius, T.A.,Vainiotalo, P.,Johnson, M.S.,Kulomaa, M.S.,Hytonen, V.P.
Rational Modification of Ligand-Binding Preference of Avidin by Circular Permutation and Mutagenesis.
Chembiochem, 9:1124-, 2008

PubMed Abstract: Chicken avidin is a key component used in a wide variety of biotechnological applications. Here we present a circularly permuted avidin (cpAvd4-->3) that lacks the loop between beta-strands 3 and 4. Importantly, the deletion of the loop has a positive effect on the binding of 4'-hydroxyazobenzene-2-carboxylic acid (HABA) to avidin. To increase the HABA affinity of cpAvd4-->3 even further, we mutated asparagine 118 on the bottom of the ligand-binding pocket to methionine, which simultaneously caused a significant drop in biotin-binding affinity. The X-ray structure of cpAvd4--> 3(N118M) allows an understanding of the effect of mutation to biotin-binding, whereas isothermal titration calorimetry revealed that the relative binding affinity of biotin and HABA had changed by over one billion-fold between wild-type avidin and cpAvd4-->3(N118M). To demonstrate the versatility of the cpAvd4-->3 construct, we have shown that it is possible to link cpAvd4-->3 and cpAvd5-->4 to form the dual-chain avidin called dcAvd2. These novel avidins might serve as a basis for the further development of self-organising nanoscale avidin building blocks.

PubMed: 18381715
DOI: 10.1002/CBIC.200700671

Experimental method

X-RAY DIFFRACTION (1.9 Å)