title: The evolution of AroA and MurA enzymes from Bacillus

authors: Oulavallickal, Tifany

subjects: ancestral sequence reconstruction

abstract: MurA and AroA are important antibacterial targets due to their essentiality in microorganisms and the absence of their respective pathways within mammals. Although much research has focussed on these enzymes, little is known about the evolution of AroA and MurA. Ancestral sequence reconstruction (ASR), a technique used to infer sequences of ancestral proteins and study their properties in the laboratory, was used to study the evolution of AroA and MurA enzymes from Bacillus. The ancestral AroA and MurA enzymes were functionally and structurally characterised and their properties compared to those of contemporary AroA and MurA.
AroA and MurA from the last common ancestor (LCA) of Bacillus along with three intermediate Bacillus MurA ancestors were inferred using ASR. The reconstructed AroA and MurA ancestral enzymes show comparable kinetic properties to the contemporary enzymes. The thermal properties of Bacillus AroA LCA, Bacillus MurA LCA and the remaining three MurA ancestors were found to be moderately thermophilic. However, the contrasting thermal profiles observed for AroA, MurA and LeuB ancestral enzymes from Bacillus at the same period of time led to the hypothesis that reconstructed ancestral enzymes provide a snapshot of the evolving host at a given point in time.
The exclusive inhibition of AroA and MurA by their inhibitors glyphosate and fosfomycin respectively remains unchanged for AroA LCA and MurA LCA. On the other hand, the high affinity for PEP and increased glyphosate sensitivity exhibited by AroA LCA indicate AroA LCA to be intermediate between class I (glyphosate sensitive) and class II (glyphosate insensitive) AroA. Characterisation of AroA LCA in vivo resulted in AroA LCA posing a fitness cost to the cells carrying this enzyme on a plasmid in a ΔaroA background. AroA LCA and MurA LCA remain highly structurally similar to the contemporary enzymes, with minor differences predominantly located on the protein surface.

text: The evolution of AroA and MurA enzymes from Bacillus MurA and AroA are important antibacterial targets due to their essentiality in microorganisms and the absence of their respective pathways within mammals. Although much research has focussed on these enzymes, little is known about the evolution of AroA and MurA. Ancestral sequence reconstruction (ASR), a technique used to infer sequences of ancestral proteins and study their properties in the laboratory, was used to study the evolution of AroA and MurA enzymes from Bacillus. The ancestral AroA and MurA enzymes were functionally and structurally characterised and their properties compared to those of contemporary AroA and MurA.
AroA and MurA from the last common ancestor (LCA) of Bacillus along with three intermediate Bacillus MurA ancestors were inferred using ASR. The reconstructed AroA and MurA ancestral enzymes show comparable kinetic properties to the contemporary enzymes. The thermal properties of Bacillus AroA LCA, Bacillus MurA LCA and the remaining three MurA ancestors were found to be moderately thermophilic. However, the contrasting thermal profiles observed for AroA, MurA and LeuB ancestral enzymes from Bacillus at the same period of time led to the hypothesis that reconstructed ancestral enzymes provide a snapshot of the evolving host at a given point in time.
The exclusive inhibition of AroA and MurA by their inhibitors glyphosate and fosfomycin respectively remains unchanged for AroA LCA and MurA LCA. On the other hand, the high affinity for PEP and increased glyphosate sensitivity exhibited by AroA LCA indicate AroA LCA to be intermediate between class I (glyphosate sensitive) and class II (glyphosate insensitive) AroA. Characterisation of AroA LCA in vivo resulted in AroA LCA posing a fitness cost to the cells carrying this enzyme on a plasmid in a ΔaroA background. AroA LCA and MurA LCA remain highly structurally similar to the contemporary enzymes, with minor differences predominantly located on the protein surface.

year: 2016

title: The paradox of sustainability definitions

authors: Dimitrov, Dara

subjects: Sustainability, definitions, worldviews,

abstract: Purpose: This paper aims to encourage debate and reflection over the increasing application of the word sustainability and the implied meanings are taken from this usage. It is argued that there are increasing numbers of sustainability definitions which are producing negative effects; that the interpretation and dissemination of sustainability definitions are not neutral in their effects of understanding sustainability. 

Design/Methodology/Approach: This paper examines how sustainability is conceptualised from two worldviews and by specifically looking at four different convening parties; how their dimensions of sustainability are linked, influence and drive the construction of the sustainability definitions in a variety of areas and in the public domain. 

Findings: This research has identified that the paradox of sustainability definitions lies in the parties who create them and not in the issues of sustainability; that often sustainability definitions do not share the same goals. 

Practical Implications: This paper seeks to bring the increasing surfeit of sustainability definitions under scrutiny and therefore extend possibilities of further research in the areas of social responsibility, ethics, claims of professionalism and accountability. 

Originality/Value: There has been little if any research that questions the validity of the sustainability definitions and how they address the issues of sustainability. It shows that the sustainability definitions can affect and shape the understanding of sustainability in a variety of areas and for a variety of parties.

text: The paradox of sustainability definitions Purpose: This paper aims to encourage debate and reflection over the increasing application of the word sustainability and the implied meanings are taken from this usage. It is argued that there are increasing numbers of sustainability definitions which are producing negative effects; that the interpretation and dissemination of sustainability definitions are not neutral in their effects of understanding sustainability. 

Design/Methodology/Approach: This paper examines how sustainability is conceptualised from two worldviews and by specifically looking at four different convening parties; how their dimensions of sustainability are linked, influence and drive the construction of the sustainability definitions in a variety of areas and in the public domain. 

Findings: This research has identified that the paradox of sustainability definitions lies in the parties who create them and not in the issues of sustainability; that often sustainability definitions do not share the same goals. 

Practical Implications: This paper seeks to bring the increasing surfeit of sustainability definitions under scrutiny and therefore extend possibilities of further research in the areas of social responsibility, ethics, claims of professionalism and accountability. 

Originality/Value: There has been little if any research that questions the validity of the sustainability definitions and how they address the issues of sustainability. It shows that the sustainability definitions can affect and shape the understanding of sustainability in a variety of areas and for a variety of parties.

year: 2010

title: Maori & Psychology Research Unit annual report 2004

authors: Rua, Mohi

subjects: Māori & Psychology Research Unit annual report

abstract: Annual report of the Maori and Psychology Research Unit (MPRU) 2004. The unit was established in August of 1997. The unit is designed to provide a catalyst and support network for enhancing research concerning the psychological needs, aspirations, and priorities of Maori people. The MPRU is well situated to draw together skilled and experienced interdisciplinary research groups by networking and establishing working relationships with staff and students within the Faculty of Arts and Social Sciences, the University, and the wider community.

text: Maori & Psychology Research Unit annual report 2004 Annual report of the Maori and Psychology Research Unit (MPRU) 2004. The unit was established in August of 1997. The unit is designed to provide a catalyst and support network for enhancing research concerning the psychological needs, aspirations, and priorities of Maori people. The MPRU is well situated to draw together skilled and experienced interdisciplinary research groups by networking and establishing working relationships with staff and students within the Faculty of Arts and Social Sciences, the University, and the wider community.

year: 2004