3SZI

Structure of apo shwanavidin (P21 form)

Summary for 3SZI

• Entry DOI: 10.2210/pdb3szi/pdb
• Related: 3EW1 3EW2 3SZH 3SZJ 3T2W 3T2X
• Descriptor: Avidin/streptavidin, FORMIC ACID (3 entities in total)
• Functional Keywords: high affinity systems, avidin, streptavidin, biotin, rhizavidin, shwanavidin, biotin-binding protein
• Biological source: Shewanella denitrificans
• Total number of polymer chains: 12
• Total formula weight: 156712.66

Authors

Livnah, O.,Meir, A. (deposition date: 2011-07-19, release date: 2012-04-25, Last modification date: 2012-06-13)

Primary citation

Meir, A.,Bayer, E.A.,Livnah, O.
Structural Adaptation of a Thermostable Biotin-binding Protein in a Psychrophilic Environment.
J.Biol.Chem., 287:17951-17962, 2012

PubMed Abstract: Shwanavidin is an avidin-like protein from the marine proteobactrium Shewanella denitrificans, which exhibits an innate dimeric structure while maintaining high affinity toward biotin. A unique residue (Phe-43) from the L3,4 loop and a distinctive disulfide bridge were shown to account for the high affinity toward biotin. Phe-43 emulates the function and position of the critical intermonomeric Trp that characterizes the tetrameric avidins but is lacking in shwanavidin. The 18 copies of the apo-monomer revealed distinctive snapshots of L3,4 and Phe-43, providing rare insight into loop flexibility, binding site accessibility, and psychrophilic adaptation. Nevertheless, as in all avidins, shwanavidin also displays high thermostability properties. The unique features of shwanavidin may provide a platform for the design of a long sought after monovalent form of avidin, which would be ideal for novel types of biotechnological application.

PubMed: 22493427
DOI: 10.1074/jbc.M112.357186

Experimental method

X-RAY DIFFRACTION (1.4 Å)