Structural and mechanistic studies on the peroxisomal oxygenase phytanoyl-CoA 2-hydroxylase (PhyH)

2007 ◽  
Vol 35 (5) ◽  
pp. 870-875 ◽  
Author(s):  
C.J. Schofield ◽  
M.A. McDonough
Keyword(s):  
Binding Sites ◽  
Point Mutations ◽  
Clinical Importance ◽  
Structure And Function ◽  
Side Chain ◽  
Mechanistic Studies ◽  
Pristanic Acid ◽  
Methyl Group ◽  
Refsum's Disease ◽  
And Function

Phytanic acid (PA) is an epimeric metabolite of the isoprenoid side chain of chlorophyll. Owing to the presence of its epimeric β-methyl group, PA cannot be metabolized by β-oxidation. Instead, it is metabolized in peroxisomes via α-oxidation to give pristanic acid, which is then oxidized by β-oxidation. PhyH (phytanoyl-CoA 2-hydroxylase, also known as PAHX), an Fe(II) and 2OG (2-oxoglutarate) oxygenase, catalyses hydroxylation of phytanoyl-CoA. Mutations of PhyH ablate its role in α-oxidation, resulting in PA accumulation and ARD (adult Refsum's disease). The structure and function of PhyH is discussed in terms of its clinical importance and unusual selectivity. Most point mutations of PhyH causing ARD cluster in two distinct groups around the Fe(II)- and 2OG-binding sites. Therapaeutic possibilities for the treatment of Refsum's disease involving PhyH are discussed.

scholarly journals The Significance of Calcium in Photosynthesis

2019 ◽  
Vol 20 (6) ◽  
pp. 1353 ◽  
Author(s):  
Quan Wang ◽  
Sha Yang ◽  
Shubo Wan ◽  
Xinguo Li
Keyword(s):  
Signal Transduction ◽  
Binding Sites ◽  
Current Knowledge ◽  
Structure And Function ◽  
Biochemical Reactions ◽  
Chloroplast Proteins ◽  
Secondary Messenger ◽  
And Function ◽  
The Relationship ◽  
Physiological And Biochemical

As a secondary messenger, calcium participates in various physiological and biochemical reactions in plants. Photosynthesis is the most extensive biosynthesis process on Earth. To date, researchers have found that some chloroplast proteins have Ca2+-binding sites, and the structure and function of some of these proteins have been discussed in detail. Although the roles of Ca2+ signal transduction related to photosynthesis have been discussed, the relationship between calcium and photosynthesis is seldom systematically summarized. In this review, we provide an overview of current knowledge of calcium’s role in photosynthesis.

The structure and function of HPr

1998 ◽  
Vol 76 (2-3) ◽  
pp. 359-367 ◽  
Author(s):  
E Bruce Waygood
Keyword(s):  
Structure And Function ◽  
Side Chain ◽  
Phosphoryl Group ◽  
Phosphotransferase System ◽  
Tertiary Structures ◽  
E Coli ◽  
H Nmr ◽  
Early Protein ◽  
Alpha Beta ◽  
And Function

Histidine-containing phosphocarrier protein, HPr, was one of the early protein tertiary structures determined by two-dimensional 1H-NMR. Tertiary structures for HPrs from Escherichia coli, Bacillus subtilis, and Staphylococcus aureus have been obtained by 1H NMR and the overall folding pattern of HPr is highly conserved, a beta alpha beta beta alpha beta alpha arrangement of three alpha-helices overlaying a four-stranded beta-sheet. High-resolution structures for HPrs from E. coli and B. subtilis have been obtained using 15N- and 13C-labeled proteins. The first application of NMR to the understanding of the structure and function of HPr was to describe the phosphohistidine isomer, Ndelta1-P-histidine in S. aureus phospho-HPr, and the unusual pKas of the His-15 side chain. The pKa values for the His-15 imidazole from more recent studies are 5.4 for HPr and 7.8 for phospho-HPr from E. coli, for example. A consensus description of the active site is proposed for HPr and phospho-HPr. In HPr, His-15 has a defined conformation and N-caps helix A, and is thus affected by the helix dipole. His-15 undergoes a small conformational change upon phosphorylation, a movement to allow the phosphoryl group to be positioned such that it forms hydrogen bonds with the main chain amide nitrogens of residue 16 (not conserved) and Arg-17. Interactions between residue 12 side chain (not conserved: asparagine, serine, and threonine) and His-15, and between the Arg-17 guanidinium group and the phosphoryl group, are either weak or transitory.Key words: HPr, NMR, phosphoenolpyruvate:sugar phosphotransferase system, phosphohistidine, phosphoserine.

scholarly journals Effect of cross-linkers on the structure and function of pig-renal sodium–glucose cotransporters after papain treatment

1998 ◽  
Vol 330 (2) ◽  
pp. 733-736 ◽  
Author(s):  
Jean GIUDICELLI ◽  
Marie-France BERTRAND ◽  
Stephane BILSKI ◽  
T. Than TRAN ◽  
Jean-Claude POIREE
Keyword(s):  
Binding Sites ◽  
Specific Inhibitor ◽  
Structure And Function ◽  
Scatchard Analysis ◽  
High Affinity ◽  
Phlorizin Binding ◽  
Sodium Dependent ◽  
Spacer Arm ◽  
Molecular Masses ◽  
And Function

Kidney brush-border membranes contain two sodium-dependent glucose transporters, one with low and one with high affinity for phlorizin, the specific inhibitor of these transporters. Using Scatchard analysis of phlorizin binding and Western blotting with specific antibodies against these transporters, we demonstrate in this study that although both transporters were proteolysed by papain treatment, only the high-affinity phlorizin-binding sites were decreased. Papain treatment followed by cross-linking with homobifunctional disuccinimidyl tartarate restored only the structure of the low-affinity phlorizin-binding protein (approx. molecular mass 70 kDa) without modifying the phlorizin-binding sites. When disuccinimidyl tartarate was replaced with dithiobis(succinimidyl acetate), another homobifunctional cross-linker with a higher spacer arm, the low- and high-affinity sites were both restored, with reappearance of two phlorizin-binding proteins with approx. molecular masses of 70 and 120 kDa. We conclude that high-affinity phlorizin-binding sites depend on the presence of the heterodimeric 120 kDa protein.

scholarly journals Filopodome mapping identifies p130Cas as a mechanosensitive regulator of filopodia stability

2018 ◽  
Author(s):  
Guillaume Jacquemet ◽  
Rafael Saup ◽  
Hellyeh Hamidi ◽  
Mitro Miihkinen ◽  
Johanna Ivaska
Keyword(s):  
Binding Sites ◽  
Focal Adhesions ◽  
Structure And Function ◽  
Structured Illumination ◽  
Structured Illumination Microscopy ◽  
Cell Adhesion And Migration ◽  
And Migration ◽  
Cellular Behaviour ◽  
And Function ◽  
Fine Tune

AbstractFilopodia are adhesive cellular protrusions specialised in the detection of extracellular matrix (ECM)-derived cues. While ECM engagement at focal adhesions is known to trigger the recruitment of hundreds of proteins (“adhesome”) to fine-tune cellular behaviour, the components of the filopodia adhesions remain undefined. Here, we performed a structured illumination microscopy-based screen to map the localisation of 80 target proteins, linked to cell adhesion and migration, within filopodia. We demonstrate preferential enrichment of several adhesion proteins to either filopodia tips, filopodia shafts, or shaft subdomains suggesting divergent, spatially restricted functions for these proteins. Moreover, proteins with phospho-inositide (PI) binding sites are particularly enriched in filopodia. This, together with the strong localisation of PI(3,4)P2 in filopodia tips, predicts critical roles for PIs in regulating filopodia ultra-structure and function. Our mapping further reveals that filopodia adhesions consist of a unique set of proteins, the filopodome, that are distinct from classical nascent adhesions, focal adhesions and fibrillar adhesions. Using live imaging, we observe that filopodia adhesions can give rise to nascent adhesions, which, in turn, form focal adhesions. Finally, we demonstrate that p130Cas (BCAR1) is recruited to filopodia tips via its CCHD domain and acts as a mechanosensitive regulator of filopodia stability.

scholarly journals Identification and Computational Analysis of 3D-Structure Of MOCS1

2021 ◽  
Author(s):  
Maham Hamid ◽  
uzma habib ◽  
Javeria Batool ◽  
Arshemah Qaisar ◽  
Rehan Zafar Paracha
Keyword(s):  
Binding Sites ◽  
Biosynthetic Pathway ◽  
Computational Analysis ◽  
Tertiary Structure ◽  
3D Structure ◽  
Structure And Function ◽  
Molybdenum Cofactor ◽  
Recognition Method ◽  
And Function ◽  
Ramachandran Plots

Abstract Cyclic pyranopterin monophosphate (cPMP) is one of the most stable intermediates in Molybdenum cofactor (MoCo) biosynthetic pathway. In humans, synthesis of cPMP from Guanosine triphosphate (GTP) requires functional genes i.e. Molybdenum Cofactor Synthesis-1 (MOCS1) genes that contains for two catalytic proteins MOCS1A and MOCS1B. Importance of MOCS1A and MOCS1B for biosynthesis of MoCo reveals from the fact that its deficiency leads to MoCo type A deficiency. As there is no structure available for MOCS1 genes in the literature, tertiary structure of MOCS1 genes were investigated in this research via threading or folds recognition method by i-TASSER and validation was done using ERRAT, Verify3D and Ramachandran plots. Binding sites were predicted and validated. Docking of MOCS1A with GTP and MOCS1B with 3, 8 dihydroguanosine was done using Autodock via PyRx. Apart from this, highly confident mutations were also predicted using SIFT and polyphen2 that can alter the structure and function of MOCS1 gene.

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