title: Crystal structure of an inferred ancestral bacterial pyruvate decarboxylase

authors: Buddrus, Lisa

subjects: Science & Technology

abstract: Pyruvate decarboxylase (PDC; EC 4.1.1.1) is a key enzyme in homofermentative metabolism where ethanol is the major product. PDCs are thiamine pyrophos­phate- and Mg2+ ion-dependent enzymes that catalyse the non-oxidative decarboxylation of pyruvate to acetaldehyde and carbon dioxide. As this enzyme class is rare in bacteria, current knowledge of bacterial PDCs is extremely limited. One approach to further the understanding of bacterial PDCs is to exploit the diversity provided by evolution. Ancestral sequence reconstruction (ASR) is a method of computational molecular evolution to infer extinct ancestral protein sequences, which can then be synthesized and experimentally characterized. Through ASR a novel PDC was generated, designated ANC27, that shares only 78% amino-acid sequence identity with its closest extant homologue (Komagataeibacter medellinensis PDC, GenBank accession No. WP_014105323.1), yet is fully functional. Crystals of this PDC diffracted to 3.5 Å resolution. The data were merged in space group P3221, with unit-cell parameters a = b = 108.33, c = 322.65 Å, and contained two dimers (two tetramer halves) in the asymmetric unit. The structure was solved by molecular replacement using PDB entry 2wvg as a model, and the final R values were Rwork = 0.246 (0.3671 in the highest resolution bin) and Rfree = 0.319 (0.4482 in the highest resolution bin). Comparison with extant bacterial PDCs supports the previously observed correlation between decreased tetramer interface area (and number of interactions) and decreased thermostability.

text: Crystal structure of an inferred ancestral bacterial pyruvate decarboxylase Pyruvate decarboxylase (PDC; EC 4.1.1.1) is a key enzyme in homofermentative metabolism where ethanol is the major product. PDCs are thiamine pyrophos­phate- and Mg2+ ion-dependent enzymes that catalyse the non-oxidative decarboxylation of pyruvate to acetaldehyde and carbon dioxide. As this enzyme class is rare in bacteria, current knowledge of bacterial PDCs is extremely limited. One approach to further the understanding of bacterial PDCs is to exploit the diversity provided by evolution. Ancestral sequence reconstruction (ASR) is a method of computational molecular evolution to infer extinct ancestral protein sequences, which can then be synthesized and experimentally characterized. Through ASR a novel PDC was generated, designated ANC27, that shares only 78% amino-acid sequence identity with its closest extant homologue (Komagataeibacter medellinensis PDC, GenBank accession No. WP_014105323.1), yet is fully functional. Crystals of this PDC diffracted to 3.5 Å resolution. The data were merged in space group P3221, with unit-cell parameters a = b = 108.33, c = 322.65 Å, and contained two dimers (two tetramer halves) in the asymmetric unit. The structure was solved by molecular replacement using PDB entry 2wvg as a model, and the final R values were Rwork = 0.246 (0.3671 in the highest resolution bin) and Rfree = 0.319 (0.4482 in the highest resolution bin). Comparison with extant bacterial PDCs supports the previously observed correlation between decreased tetramer interface area (and number of interactions) and decreased thermostability.

year: 2018

title: The inherent liminality of lesbian detectives: Shifting spaces and lesbian crime fiction 1984-2022

authors: Antoniolli, Claudia

subjects: Crime fiction

abstract: This thesis studies lesbian detective fiction and specifically considers this genre in its early decades (1980s-1990s) from the United States, United Kingdom, Australia, and New Zealand. This thesis postulates that out of a sample pool of a hundred novels, there are recurring patterns of behaviours and attitudes among the protagonists of this genre within certain physical and metaphorical spaces. These patterns demonstrate a destabilised identity, as the lesbian sleuth never ceases to explore and test the boundaries of her authority as an enforcer of law and order and of her suppressed spatiality as a member of a sexual minority. This causes her to live in a perpetual state of Insider/Outsider liminality and it causes queer trauma to be a fundamental aspect of her character. This thesis considers this concept as the result of long-standing, systemic homophobia and heterosexist normativity, and utilises the notion of queer trauma to interpret the way the lesbian sleuth is inescapably stuck between a sense of duty and justice and a yearning for belonging and self-affirmation. The interpretive process is supported by an extensive and in-depth theoretical research into the fields of history, culture, geography, feminist criticism, gender, and sexuality studies for the selected subject matter. The spaces selected and analysed in this thesis are the queer closet, the medical establishment, domestic settings, and the gay bar. These spaces have been chosen for the significant, emblematic ways in which the lesbian detectives interact with them and have been analysed in order of their importance for the protagonists’ characterisation. The introduction includes introductory statements and the theoretical framework, the first chapter overviews major detectives in the history of crime literature from a spatial perspective; the second chapter discusses the queer closet; the third chapter considers the space of the clinic and the topics of queer trauma and of the pathologisation of homosexuality; the fourth chapter analyses the domestic settings of the protagonists; the fifth chapter examines the context of the gay bar and its history; finally, the conclusion offers closing statements about the focus and originality of this thesis. The originality of this thesis lies in its focus on spaces and on the relationship between the protagonist and society, law and order, and Self and Other. This thesis contributes to the knowledge of queer literature by specifically considering the unescapable liminality of the lesbian/Outsider detective/Insider.

text: The inherent liminality of lesbian detectives: Shifting spaces and lesbian crime fiction 1984-2022 This thesis studies lesbian detective fiction and specifically considers this genre in its early decades (1980s-1990s) from the United States, United Kingdom, Australia, and New Zealand. This thesis postulates that out of a sample pool of a hundred novels, there are recurring patterns of behaviours and attitudes among the protagonists of this genre within certain physical and metaphorical spaces. These patterns demonstrate a destabilised identity, as the lesbian sleuth never ceases to explore and test the boundaries of her authority as an enforcer of law and order and of her suppressed spatiality as a member of a sexual minority. This causes her to live in a perpetual state of Insider/Outsider liminality and it causes queer trauma to be a fundamental aspect of her character. This thesis considers this concept as the result of long-standing, systemic homophobia and heterosexist normativity, and utilises the notion of queer trauma to interpret the way the lesbian sleuth is inescapably stuck between a sense of duty and justice and a yearning for belonging and self-affirmation. The interpretive process is supported by an extensive and in-depth theoretical research into the fields of history, culture, geography, feminist criticism, gender, and sexuality studies for the selected subject matter. The spaces selected and analysed in this thesis are the queer closet, the medical establishment, domestic settings, and the gay bar. These spaces have been chosen for the significant, emblematic ways in which the lesbian detectives interact with them and have been analysed in order of their importance for the protagonists’ characterisation. The introduction includes introductory statements and the theoretical framework, the first chapter overviews major detectives in the history of crime literature from a spatial perspective; the second chapter discusses the queer closet; the third chapter considers the space of the clinic and the topics of queer trauma and of the pathologisation of homosexuality; the fourth chapter analyses the domestic settings of the protagonists; the fifth chapter examines the context of the gay bar and its history; finally, the conclusion offers closing statements about the focus and originality of this thesis. The originality of this thesis lies in its focus on spaces and on the relationship between the protagonist and society, law and order, and Self and Other. This thesis contributes to the knowledge of queer literature by specifically considering the unescapable liminality of the lesbian/Outsider detective/Insider.

year: 2023

title: Waitangi Soda Springs alum dosing – bioavailability of aluminium 2013

authors: Ling, Nicholas

abstract: Continuous alum dosing of the Waitangi Soda Springs at Lake Rotoehu commenced in 2010 to reduce inflows of dissolved reactive phosphorus to Lake Rotoehu. Analyses of bioaccumulation in the tissues of kōura and goldfish from Lake Rotoehu were undertaken on animals collected in September 2013 to determine the bioavailability and bioaccumulation of aluminium. Comparative analyses were undertaken on kōura and goldfish collected from Lakes Rotorua and Rotoiti. Lake Rotoehu kōura and goldfish showed slightly elevated aluminium concentrations in the gills indicating enhanced exposure to aluminium but little evidence for significant bioaccumulation in tissues.

text: Waitangi Soda Springs alum dosing – bioavailability of aluminium 2013 Continuous alum dosing of the Waitangi Soda Springs at Lake Rotoehu commenced in 2010 to reduce inflows of dissolved reactive phosphorus to Lake Rotoehu. Analyses of bioaccumulation in the tissues of kōura and goldfish from Lake Rotoehu were undertaken on animals collected in September 2013 to determine the bioavailability and bioaccumulation of aluminium. Comparative analyses were undertaken on kōura and goldfish collected from Lakes Rotorua and Rotoiti. Lake Rotoehu kōura and goldfish showed slightly elevated aluminium concentrations in the gills indicating enhanced exposure to aluminium but little evidence for significant bioaccumulation in tissues.

year: 2015