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: Managed Aquifer Recharge in the Poverty Bay Flats

authors: Hampton, G. W.

abstract: In 2012 a report was commissioned by the Gisborne District Council (GDC) to examine groundwater resources in the Poverty Bay flats. This report found that groundwater elevations within the Makauri Gravel aquifer (the aquifer subject to the greatest groundwater abstractions), were declining at statistically significant rates, probably due to groundwater abstractions (White et al., 2012). As a result, the GDC is investigating whether managed aquifer recharge (MAR) can be used to help achieve the sustainable management of groundwater resources within the Poverty Bay flats. MAR is “the purposeful recharge of water to aquifers for subsequent recovery or environmental benefit” (Dillon et al., 2013, p. 2). Though MAR is uncommon in New Zealand, increasing pressures on groundwater may change this. GDC is investigating two different methods of MAR, well-injection (in conjunction with Golder Associates), and infiltration basins, which is the focus of this study.

text: Managed Aquifer Recharge in the Poverty Bay Flats In 2012 a report was commissioned by the Gisborne District Council (GDC) to examine groundwater resources in the Poverty Bay flats. This report found that groundwater elevations within the Makauri Gravel aquifer (the aquifer subject to the greatest groundwater abstractions), were declining at statistically significant rates, probably due to groundwater abstractions (White et al., 2012). As a result, the GDC is investigating whether managed aquifer recharge (MAR) can be used to help achieve the sustainable management of groundwater resources within the Poverty Bay flats. MAR is “the purposeful recharge of water to aquifers for subsequent recovery or environmental benefit” (Dillon et al., 2013, p. 2). Though MAR is uncommon in New Zealand, increasing pressures on groundwater may change this. GDC is investigating two different methods of MAR, well-injection (in conjunction with Golder Associates), and infiltration basins, which is the focus of this study.

year: 2015-11

title: Breaking barriers and empowering perspectives: Centering women's voices in the mongrel mob wāhine toa

authors: Arnold, Annaliese

subjects: gang research

abstract: Gang communities in Aotearoa New Zealand have traditionally been sites of masculinity where specific forms of 'maleness' - including resistance to authority, antisocial behaviour, and expressions of violence - are embraced, expressed, and enforced through various internal cultural norms and reactions to the outside world. The dominant narrative that informs public perceptions of New Zealand gangs is often centered on crime, poverty, and Indigeneity. Much less is known about the role of women in these communities, particularly as their voices have only recently emerged from one of the largest gang chapters in the country. This research, conducted in close collaboration with wāhine within the Mongrel Mob Kingdom's first female-only chapter, Mongrel Mob Wāhine Toa, uses a participatory action research approach with photovoice methodology. Drawing on the personal narratives of six wāhine, this study aims to better understand their perspectives and experiences of contributing to a fledgling movement that privileges women within a predominantly male-centered gang environment. Photovoice is used alongside semi-structured interviews to provide depth and breadth to the data, allowing the wāhine to visually and verbally express their experiences and perspectives. Themes include navigating marginality, empowerment, and resistance. The long-range goal of this work is to inform context-sensitive policies and interventions for wāhine in gangs in Aotearoa. By foregrounding the perspective of wāhine, this study contributes to breaking down barriers and reshaping discourses around women in gangs, with implications for well-being and empowerment.

text: Breaking barriers and empowering perspectives: Centering women's voices in the mongrel mob wāhine toa Gang communities in Aotearoa New Zealand have traditionally been sites of masculinity where specific forms of 'maleness' - including resistance to authority, antisocial behaviour, and expressions of violence - are embraced, expressed, and enforced through various internal cultural norms and reactions to the outside world. The dominant narrative that informs public perceptions of New Zealand gangs is often centered on crime, poverty, and Indigeneity. Much less is known about the role of women in these communities, particularly as their voices have only recently emerged from one of the largest gang chapters in the country. This research, conducted in close collaboration with wāhine within the Mongrel Mob Kingdom's first female-only chapter, Mongrel Mob Wāhine Toa, uses a participatory action research approach with photovoice methodology. Drawing on the personal narratives of six wāhine, this study aims to better understand their perspectives and experiences of contributing to a fledgling movement that privileges women within a predominantly male-centered gang environment. Photovoice is used alongside semi-structured interviews to provide depth and breadth to the data, allowing the wāhine to visually and verbally express their experiences and perspectives. Themes include navigating marginality, empowerment, and resistance. The long-range goal of this work is to inform context-sensitive policies and interventions for wāhine in gangs in Aotearoa. By foregrounding the perspective of wāhine, this study contributes to breaking down barriers and reshaping discourses around women in gangs, with implications for well-being and empowerment.

year: 2025