scholarly journals The Crystal Structure of Rv0813c from Mycobacterium tuberculosis Reveals a New Family of Fatty Acid-Binding Protein-Like Proteins in Bacteria

2006 ◽  
Vol 189 (5) ◽  
pp. 1899-1904 ◽  
Author(s):  
William Shepard ◽  
Ahmed Haouz ◽  
Martin Graña ◽  
Alejandro Buschiazzo ◽  
Jean-Michel Betton ◽  
...  

ABSTRACT The gene Rv0813c from Mycobacterium tuberculosis, which codes for a hypothetical protein of unknown function, is conserved within the order Actinomycetales but absent elsewhere. The crystal structure of Rv0813c reveals a new family of proteins that resemble the fatty acid-binding proteins (FABPs) found in eukaryotes. Rv0813c adopts the 10-stranded β-barrel fold typical of FABPs but lacks the double-helix insert that covers the entry to the binding site in the eukaryotic proteins. The barrel encloses a deep cavity, at the bottom of which a small cyclic ligand was found to bind to the hydroxyl group of Tyr192. This residue is part of a conserved Arg-X-Tyr motif much like the triad that binds the carboxylate group of fatty acids in FABPs. Most of the residues forming the internal surface of the cavity are conserved in homologous protein sequences found in CG-rich prokaryotes, strongly suggesting that Rv0813c is a member of a new family of bacterial FABP-like proteins that may have roles in the recognition, transport, and/or storage of small molecules in the bacterial cytosol.

2019 ◽  
Vol 476 (19) ◽  
pp. 2815-2834 ◽  
Author(s):  
Andy M. Lau ◽  
Henna Zahid ◽  
Jayesh Gor ◽  
Stephen J. Perkins ◽  
Alun R. Coker ◽  
...  

Abstract Human zinc-α2-glycoprotein (ZAG) is a 42 kDa adipokine which regulates body fat mass and is associated with cachexia and obesity. ZAG belongs to the major histocompatibility complex class I protein family and binds long-chain polyunsaturated fatty acids in its groove formed from the α1 and α2 domains. To identify the molecular basis of its lipid-binding function, we determined the first crystal structure at 2.49 Å resolution for fatty acid-bound ZAG, where the ligand was the fluorescent 11-(dansylamino)undecanoic acid (DAUDA). The 192 kDa crystallographic asymmetric unit contained six ZAG and eight fatty acid molecules in unique conformations. Six fatty acid molecules were localised to the ZAG grooves, where their tails were bound in two distinct conformations. The carboxylate groups of three fatty acids projected out of the groove, while the fourth was hydrogen bonded with R73 inside the groove. Other ligand-residue contacts were primarily hydrophobic. A new fatty acid site was revealed for two further DAUDA molecules at the ZAG α3 domains. Following conformational changes from unbound ZAG, the α3 domains formed tetrameric β-barrel structures lined by fatty acid molecules that doubled the binding capacity of ZAG. Analytical ultracentrifugation revealed that ZAG in solution was a monomer in the absence of DAUDA, but formed small amounts of tetramers with DAUDA. By showing that ZAG binds fatty acids in different locations, we demonstrate an augmented mechanism for fatty acid binding in ZAG that is distinct from other known fatty acid binding proteins, and may be relevant to cachexia.


1984 ◽  
Vol 259 (21) ◽  
pp. 13395-13401 ◽  
Author(s):  
P Brecher ◽  
R Saouaf ◽  
J M Sugarman ◽  
D Eisenberg ◽  
K LaRosa

2021 ◽  
Vol 10 (8) ◽  
pp. 1567
Author(s):  
Katarzyna Konończuk ◽  
Eryk Latoch ◽  
Beata Żelazowska-Rutkowska ◽  
Maryna Krawczuk-Rybak ◽  
Katarzyna Muszyńska-Rosłan

Childhood cancer survivors are highly exposed to the development of side effects after many years of cessation of anticancer treatment, including altered lipid metabolism that may result in an increased risk of overweight and metabolic syndrome. Adipocyte (A-FABP) and epidermal (E-FABP) fatty acid-binding proteins are expressed in adipocytes and are assumed to play an important role in the development of lipid disturbances leading to the onset of metabolic syndrome. The aim of this study was to investigate the association between serum A-FABP and E-FABP levels, overweight, and components of the metabolic syndrome in acute lymphoblastic leukemia survivors. Sixty-two acute lymphoblastic leukemia (ALL) survivors (34 females) were included in the study. The mean age at the time of the study was 12.41 ± 4.98 years (range 4.71–23.43). Serum levels of A-FABP and E-FABP were analyzed using a commercially available ELISA kit. The ALL survivors presented statistically higher A-FABP levels in comparison with the healthy controls (25.57 ± 14.46 vs. 15.13 ± 7.61 ng/mL, p < 0.001). The subjects with body mass index (BMI) above the normal range (18 overweight, 10 obese) had a greater level of A-FABP compared to the ALL group with normal BMI (32.02 ± 17.10 vs. 20.33 ± 9.24 ng/mL, p = 0.006). Of all participants, 53.23% had at least one risk factor of metabolic syndrome; in this group, only the A-FABP level showed a statistically significant difference compared to the healthy control group (30.63 ± 15.91 vs. 15.13 ± 7.61 ng/mL, p < 0.001). The subjects with two or more metabolic risk factors (16.13%) presented higher levels of both A-FABP (33.62 ± 17.16 vs. 15.13 ± 7.61 ng/mL, p = 0.001) and E-FABP (13.37 ± 3.62 vs. 10.12 ± 3.21 ng/mL, p = 0.021) compared to the controls. Univariable regression models showed significant associations between BMI and systolic blood pressure with the A-FABP level (coeff. 1.02 and 13.74, respectively; p < 0.05). In contrast, the E-FABP level was only affected by BMI (coeff. 0.48; p < 0.01). The findings reported herein suggest that the increased levels of A-FABP and E-FABP may be involved in the pathogenesis of overweight and the onset of metabolic syndrome in acute lymphoblastic leukemia. However, further longitudinal, prospective studies of fatty acid-binding proteins and their potential role in the pathogenesis of obesity and metabolic syndrome in ALL survivors remain to be performed.


Sign in / Sign up

Export Citation Format

Share Document