scholarly journals Crystal Structure of the Carbon-Phosphorus Lyase Complex from Escherichia coli

2014 ◽  
Vol 70 (a1) ◽  
pp. C1060-C1060
Author(s):  
Paulina Seweryn ◽  
Lan Van ◽  
Morten Kjeldgaard ◽  
Bjarne Hove-Jensen ◽  
Bjarne Jochimsen ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Bond Cleavage ◽  
Essential Element ◽  
Degradation Pathway ◽  
Enzyme Mechanism ◽  
Radical Mechanism ◽  
Stable Carbon ◽  
Number Of Microorganisms ◽  
Carbon Phosphorus Lyase ◽  
Insight Into

Phosphorus is an essential element for all living cells and is usually taken up in the form of phosphate. A number of microorganisms, however, are capable of extracting phosphorous from organic phosphonate compounds, which are characterized by a stable carbon-phosphorus (C-P) bond (1). The metabolic pathway responsible for phosphonate degradation is still poorly understood, but the process is known to involve two reactions before the actual C-P bond cleavage, which has been proposed to take place via a radical mechanism. A key component in the process is C-P lyase, an enzyme encoded by phnJ within the phn operon (2). To get a better insight into the mechanism of this complex degradation pathway, we have determined the crystal structure of the core of a multi-subunit enzymatic complex including the C-P lyase component with a total molecular mass of 220 kDa (3). The structure reveals the overall architecture of the C-P lyase and has important implications for our understanding of enzyme mechanism and catalysis.

The Crystal Structure ofBacillus cereusPhosphonoacetaldehyde Hydrolase:  Insight into Catalysis of Phosphorus Bond Cleavage and Catalytic Diversification within the HAD Enzyme Superfamily†,‡

Biochemistry ◽  
2000 ◽  
Vol 39 (34) ◽  
pp. 10385-10396 ◽  
Author(s):  
Marc C. Morais ◽  
Wenhai Zhang ◽  
Angela S. Baker ◽  
Guofeng Zhang ◽  
Debra Dunaway-Mariano ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Bond Cleavage ◽  
Enzyme Superfamily ◽  
Insight Into

scholarly journals Bag6 complex contains a minimal tail-anchor–targeting module and a mock BAG domain

2014 ◽  
Vol 112 (1) ◽  
pp. 106-111 ◽  
Author(s):  
Jee-Young Mock ◽  
Justin William Chartron ◽  
Ma’ayan Zaslaver ◽  
Yue Xu ◽  
Yihong Ye ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Endoplasmic Reticulum ◽  
Complex Network ◽  
Binding Sites ◽  
Transmembrane Domain ◽  
Degradation Pathway ◽  
Tetratricopeptide Repeat ◽  
Endoplasmic Reticulum Associated Degradation ◽  
Structural Insight ◽  
Insight Into

BCL2-associated athanogene cochaperone 6 (Bag6) plays a central role in cellular homeostasis in a diverse array of processes and is part of the heterotrimeric Bag6 complex, which also includes ubiquitin-like 4A (Ubl4A) and transmembrane domain recognition complex 35 (TRC35). This complex recently has been shown to be important in the TRC pathway, the mislocalized protein degradation pathway, and the endoplasmic reticulum-associated degradation pathway. Here we define the architecture of the Bag6 complex, demonstrating that both TRC35 and Ubl4A have distinct C-terminal binding sites on Bag6 defining a minimal Bag6 complex. A crystal structure of the Bag6–Ubl4A dimer demonstrates that Bag6–BAG is not a canonical BAG domain, and this finding is substantiated biochemically. Remarkably, the minimal Bag6 complex defined here facilitates tail-anchored substrate transfer from small glutamine-rich tetratricopeptide repeat-containing protein α to TRC40. These findings provide structural insight into the complex network of proteins coordinated by Bag6.

scholarly journals Crystal Structure of PhnH: an Essential Component of Carbon-Phosphorus Lyase in Escherichia coli

2007 ◽  
Vol 190 (3) ◽  
pp. 1072-1083 ◽  
Author(s):  
Melanie A. Adams ◽  
Yan Luo ◽  
Bjarne Hove-Jensen ◽  
Shu-Mei He ◽  
Laura M. van Staalduinen ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Escherichia Coli ◽  
Bond Cleavage ◽  
Binding Pocket ◽  
Conserved Residues ◽  
Chemical Hydrolysis ◽  
Carbon Phosphorus Lyase ◽  
Cyclic Compounds ◽  
Potential Ligand ◽  
Reduced Forms

ABSTRACT Organophosphonates are reduced forms of phosphorous that are characterized by the presence of a stable carbon-phosphorus (C-P) bond, which resists chemical hydrolysis, thermal decomposition, and photolysis. The chemically inert nature of the C-P bond has raised environmental concerns as toxic phosphonates accumulate in a number of ecosystems. Carbon-phosphorous lyase (CP lyase) is a multienzyme pathway encoded by the phn operon in gram-negative bacteria. In Escherichia coli 14 cistrons comprise the operon (phnCDEFGHIJKLMNOP) and collectively allow the internalization and degradation of phosphonates. Here we report the X-ray crystal structure of the PhnH component at 1.77 Å resolution. The protein exhibits a novel fold, although local similarities with the pyridoxal 5′-phosphate-dependent transferase family of proteins are apparent. PhnH forms a dimer in solution and in the crystal structure, the interface of which is implicated in creating a potential ligand binding pocket. Our studies further suggest that PhnH may be capable of binding negatively charged cyclic compounds through interaction with strictly conserved residues. Finally, we show that PhnH is essential for C-P bond cleavage in the CP lyase pathway.

Crystal Structure ofEscherichia coliKetopantoate Reductase at 1.7 Å Resolution and Insight into the Enzyme Mechanism†

Biochemistry ◽  
2001 ◽  
Vol 40 (48) ◽  
pp. 14493-14500 ◽  
Author(s):  
Dijana Matak-Vinković ◽  
Mladen Vinković ◽  
S. Adrian Saldanha ◽  
Jennifer L. Ashurst ◽  
Frank von Delft ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Enzyme Mechanism ◽  
Insight Into

Crystal structure of KBSi3O8 isostructural with danburite

1993 ◽  
Vol 57 (386) ◽  
pp. 157-164 ◽  
Author(s):  
Mitsuyoshi Kimata
Keyword(s):  
Crystal Structure ◽  
Direct Method ◽  
Crystal Chemical ◽  
Chemical Formula ◽  
Crystal Chemical Formula ◽  
3 Dimensional ◽  
Tetrahedral Sites ◽  
Structural Types ◽  
Coupled Substitution ◽  
Insight Into

AbstractThe crystal structure of KBSi3O8 (orthorhombic, Pnam, with a = 8.683(1), b = 9.253(1), c = 8.272(1) Å,, V = 664.4(1) Å3, Z = 4) has been determined by the direct method applied to 3- dimensional rcflection data. The structure of a microcrystal with the dimensions 20 × 29 × 37 μm was refined to an unweightcd residual of R = 0.031 using 386 non-zero structure amplitudes. KBSi3O8 adopts a structure essentially different from recdmergneritc NaBSi3O8, with the low albite (NaAlSi3O8) structure, and isotypic with danburite CaB2Si2Os which has the same topology as paracelsian BaAl2Si2O8. The chenfical relationship between this sample and danburitc gives insight into a new coupled substitution; K+ + Si4+ = Ca2+ + B3+ in the extraframework and tetrahedral sites. The present occupancy refinement revealed partial disordering of B and Si atoms which jointly reside in two kinds of general equivalent points, T(1) and T(2) sites. Thus the expanded crystal-chemical formula can be written in the form K(B0.44Si0.56)2(B0.06Si0.94)2O8The systematic trend among crystalline compounds with the M+T3+T4+3O8 formula suggests that they exist in one of four structural types; the feldspar structures with T3+/T4+ ordered and/or disordered forms, and the paracelsian and the hollandite structures.

Insight into the physics of the 5f -band antiferromagnet U2Ni2Sn from the pressure dependence of crystal structure and electrical resistivity

2021 ◽  
Vol 103 (3) ◽  
Author(s):  
Silvie Maskova-Cerna ◽  
Alexandre Kolomiets ◽  
Jiri Prchal ◽  
Itzhak Halevy ◽  
Volodymyr Buturlim ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Electrical Resistivity ◽  
Pressure Dependence ◽  
Insight Into

An analysis of pragmatic content in EFL textbooks for young learners in Croatia

2021 ◽  
pp. 136216882098693
Author(s):  
Eva Jakupčević ◽  
Mihajla Ćavar Portolan
Keyword(s):  
Second Language ◽  
Language Learners ◽  
Speech Acts ◽  
Primary Schools ◽  
Communicative Competence ◽  
Essential Element ◽  
Pragmatic Competence ◽  
Young Learners ◽  
Language Classes ◽  
Insight Into

Pragmatic competence is an essential element of communicative competence, which makes it relevant for speakers of all ages, including young language learners (YLLs). Despite the recognized importance of pragmatics, research of textbooks for adult second language (L2) learners to date has found them lacking in their approach to this key aspect of language. However, there is very little research of pragmatics in textbooks for YLLs, which would provide insight into the extent to which these materials can support teachers in including elements of pragmatic competence into their language classes. The present study aims to fill this gap by determining how much pragmatic content is included in 18 textbooks used in Croatian primary schools with learners aged 9–12 years. The textbooks are compared in regard to the percentage of pages with pragmatic content as well as the different speech acts that receive explicit attention in them. The main finding of the study is the great amount of inconsistency when it comes to the scope and treatment of pragmatic content, with some textbooks proving extremely lacking. The results present a concerning picture as all of the students using these diverse textbooks should be following the same curriculum which emphasizes the development of communicative competence.

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