title: Structural and functional characterization of a promiscuous feruloyl esterase (Est1E) from the rumen bacterium Butyrivibrio proteoclasticus

authors: Goldston, David C.

subjects: rumen

abstract: The release of polysaccharide from the plant cell wall is a key process to release the stored energy from plant biomass. Within the ruminant digestive system, a host of commensal microorganisms speed the breakdown of plant cell matter releasing fermentable sugars. The presence of phenolic compounds, most notably ferulic acid (FA), esterified within the cell wall is thought to pose a significant impediment to the degradation of the plant cell wall. The structure of a FA esterase from the ruminant bacterium Butyrivibrio proteoclasticus has been determined in two different space groups, in both the apo-form, and the ligand bound form with FA located in the active site. The structure reveals a new lid domain that has no structural homologues in the PDB. The flexibility of the lid domain is evident by the presence of three different conformations adopted by different molecules in the crystals. In the FA-bound structures, these conformations show sequential binding and closing of the lid domain over the substrate. Enzymatic activity assays demonstrate a broad activity against plant-derived hemicellulose, releasing at least four aromatic compounds including FA, coumaric acid, coumarin-3-carboxylic acid, and cinnamic acid. The rumen is a complex ecosystem that efficiently degrades plant biomass and the genome of B. proteoclasticus contains greater than 130 enzymes, which are potentially involved in this process of which Est1E is the first to be well characterized.

text: Structural and functional characterization of a promiscuous feruloyl esterase (Est1E) from the rumen bacterium Butyrivibrio proteoclasticus The release of polysaccharide from the plant cell wall is a key process to release the stored energy from plant biomass. Within the ruminant digestive system, a host of commensal microorganisms speed the breakdown of plant cell matter releasing fermentable sugars. The presence of phenolic compounds, most notably ferulic acid (FA), esterified within the cell wall is thought to pose a significant impediment to the degradation of the plant cell wall. The structure of a FA esterase from the ruminant bacterium Butyrivibrio proteoclasticus has been determined in two different space groups, in both the apo-form, and the ligand bound form with FA located in the active site. The structure reveals a new lid domain that has no structural homologues in the PDB. The flexibility of the lid domain is evident by the presence of three different conformations adopted by different molecules in the crystals. In the FA-bound structures, these conformations show sequential binding and closing of the lid domain over the substrate. Enzymatic activity assays demonstrate a broad activity against plant-derived hemicellulose, releasing at least four aromatic compounds including FA, coumaric acid, coumarin-3-carboxylic acid, and cinnamic acid. The rumen is a complex ecosystem that efficiently degrades plant biomass and the genome of B. proteoclasticus contains greater than 130 enzymes, which are potentially involved in this process of which Est1E is the first to be well characterized.

year: 2010

title: Probability models and uncertainty in hydrology: Some personal reflections

authors: Bardsley, W. Earl

abstract: Even minimal hydrological information can be of value with uncertainty. Probability distribution models provide a unified approach to a range of hydrological analyses.

text: Probability models and uncertainty in hydrology: Some personal reflections Even minimal hydrological information can be of value with uncertainty. Probability distribution models provide a unified approach to a range of hydrological analyses.

year: 2012

title: An indigenous psychologies teaching and research hub : Enabling our resources, strengths and histories

authors: Nikora, Linda Waimarie

abstract: This paper was presented as part of an informal indigenous psychologies dialogue session at the Australian Psychological Society's annual conference. In this paper, we present the concept of an indigenous psychologies teaching and research hub that reduces distance, helps students remain in community, uses resources efficiency, and has the capacity to bring indigenous psychologist and academics into closer communication.

text: An indigenous psychologies teaching and research hub : Enabling our resources, strengths and histories This paper was presented as part of an informal indigenous psychologies dialogue session at the Australian Psychological Society's annual conference. In this paper, we present the concept of an indigenous psychologies teaching and research hub that reduces distance, helps students remain in community, uses resources efficiency, and has the capacity to bring indigenous psychologist and academics into closer communication.

year: 2014