2KP5

NMR structure of Hahellin, a beta-gamma crystallin

Summary for 2KP5

• Entry DOI: 10.2210/pdb2kp5/pdb
• NMR Information: BMRB: 15743
• Descriptor: Putative uncharacterized protein (1 entity in total)
• Functional Keywords: beta-gamma crystallin, calcium-binding protein, bacterial, unknown function
• Biological source: Hahella chejuensis
• Total number of polymer chains: 1
• Total formula weight: 10262.29

Authors

Srivastava, A.K.,Sharma, Y.,Chary, K.V. (deposition date: 2009-10-07, release date: 2010-11-10, Last modification date: 2025-05-07)

Primary citation

Srivastava, A.K.,Sharma, Y.,Chary, K.V.
A natively unfolded beta gamma-crystallin domain from Hahella chejuensis.
Biochemistry, 49:9746-9755, 2010

PubMed Abstract: To date, very few βγ-crystallins have been identified and structurally characterized. Several of them have been shown to bind Ca(2+) and thereby enhance their stability without any significant change in structure. Although Ca(2+)-induced conformational changes have been reported in two putative βγ-crystallins from Caulobacter crescentus and Yersinia pestis, they are shown to be partially unstructured, and whether they acquire a βγ-crystallin fold is not known. We describe here a βγ-crystallin domain, hahellin, its Ca(2+) binding properties and NMR structure. Unlike any other βγ-crystallin, hahellin is characterized as a pre-molten globule (PMG) type of natively unfolded protein domain. It undergoes drastic conformational change and acquires a typical βγ-crystallin fold upon Ca(2+) binding and hence acts as a Ca(2+)-regulated conformational switch. However, it does not bind Mg(2+). The intrinsically disordered Ca(2+)-free state and the close structural similarity of Ca(2+)-bound hahellin to a microbial βγ-crystallin homologue, Protein S, which shows Ca(2+)-dependent stress response, make it a potential candidate for the cellular functions. This study indicates the presence of a new class of natively unfolded βγ-crystallins and therefore the commencement of the possible functional roles of such proteins in this superfamily.

PubMed: 20929244
DOI: 10.1021/bi101000m

Experimental method

SOLUTION NMR