SASDC55: Plasmodium falciparum p23A (CS domain protein, putative, Pfp23A)

Basic information

• Entry: Database: SASBDB / ID: SASDC55

Sample

Plasmodium falciparum p23A

• CS domain protein, putative (protein), Pfp23A, Plasmodium falciparum (isolate 3D7)

• Function / homology: NudC family / CS domain / CS domain / CS domain profile. / HSP20-like chaperone / unfolded protein binding / protein folding / cytoplasm / HSP90 co-chaperone p23
• Biological species: Plasmodium falciparum (isolate 3D7) (eukaryote)
• Citation: Journal: Int J Biol Macromol / Year: 2018; Title: Comparative studies of the low-resolution structure of two p23 co-chaperones for Hsp90 identified in Plasmodium falciparum genome.; Authors: Noeli S M Silva / Thiago V Seraphim / Karine Minari / Leandro R S Barbosa / Júlio C Borges / ; Abstract: The p23 proteins are small acidic proteins that aid the functional cycle of the Hsp90 molecular chaperone. Such co-chaperone acts by temporarily inhibiting the ATPase activity of Hsp90 and exhibits intrinsic chaperone activity, suggesting independent roles. A search for p23 in the Plasmodium falciparum genome led to the identification of two putative proteins showing 13% identity to each other and approximately 20% identity to human p23. To understand the presence of two p23 proteins in this organism, we generated recombinant p23 proteins (Pfp23A and Pfp23B) and investigated their structure and function. The proteins presented some similarities and dissimilarities in structural contents and showed different chemical and thermal stabilities, with Pfp23A being more stable than Pfp23B, suggesting that these proteins may present different functions in this organism. Both Pfp23 proteins behaved as elongated monomers in solution and were capable of preventing the thermal-induced aggregation of model client proteins with different efficiencies. Finally, the Pfp23 proteins inhibited the ATPase activity of recombinant P. falciparum Hsp90 (PfHsp90). These results validate the studied proteins as p23 proteins and co-chaperones of PfHsp90.

Contact author

• Júlio Borges (Instituto de Química de São Carlos, São Carlos - SP - Brasil)

Models

• Model #1316: ; Type: dummy / Software: (5.0) / Radius of dummy atoms: 2.00 A / Symmetry: P1 / Comment: Average of 10 models generated by DAMMIN / Chi-square value: 0.685; Search similar-shape structures of this assembly by Omokage search (details)

Sample

• Sample: Name: Plasmodium falciparum p23A / Specimen concentration: 2.50-5.00
• Buffer: Name: 25 mM Tris-HCl, 100 mM NaCl, 2 mM EDTA, 1 mM B-mercaptoethanol; pH: 7.4

Entity #700

Name: Pfp23A / Type: protein / Description: CS domain protein, putative / Formula weight: 18.65 / Num. of mol.: 1 / Source: Plasmodium falciparum (isolate 3D7) / References: UniProt: Q8I2N9
Sequence:

GSHMGEIYNK RHKYMNNGVL IYEWEQSIDE INIYIDMNSK LVNKNDLNIE IKSKRITIGL KNTKNFLEGE LFSIIDEDCS YWFIEDNNLH ILLTKVKKGE SWNSVFKGHK NLNPVDEDNT KKQILLERFQ QEYPNFDFSS ASFNGQVPDA RTFMGGLKY

Experimental information

• Beam: Instrument name: Brazilian Synchrotron Light Laboratory SAXS2 Beamline; City: Campinas / 国: Brazil / Type of source: X-ray synchrotronSynchrotron / Wavelength: 0.1488 Å / Dist. spec. to detc.: 1 mm
• Detector: Name: MAR 165 CCD

Scan

Title: Plasmodium falciparum p23A / Measurement date: May 26, 2015 / Storage temperature: 4 °C / Cell temperature: 20 °C / Exposure time: 180 sec. / Number of frames: 1 / Unit: 1/nm /

	Min	Max
Q	0.1838	3.1807

Distance distribution function P(R)

Sofotware P(R): GNOM 4.6 / Number of points: 238 /

	Min	Max
Q	0.01838	0.3181
P(R) point	1	238
R	0	85

Result

Experimental MW: 21 kDa / Type of curve: merged

	P(R)	P(R) error	Guinier	Guinier error
Forward scattering, I0	0.01292	0.000139	0.012933	7.5E-5
Radius of gyration, Rg	2.55 nm	0.03	2.47 nm	0.09

	Min	Max	Error
D	-	8.5	5
Guinier point	1	29	-