ABHISHEK ANTIBIOTICS PPT MICROBIOLOGY // USES OF ANTIOBIOTICS TYPES OF ANTIB...
January highlights
1. Recognition for BSISB Scientific Achievements
FACSS (Federation of Analytical Chemistry and
Spectroscopy Societies) Poster Award at the 2016
SCIX (the great SCIentific eXchange) Conference
For “Plasmonic graded gratings for hyperspectral near-field
infrared sensing and imaging” by Arthur Montazeri, Nazir
Kherani, and Hoi-Ying Holman
France-Berkeley Fund (FBF)
For “Plasmon-assisted synthesis of ultra-precise designer-nanoparticles”
prepared by Arthur Montazeri (in collaboration with Prof. Roya
Maboudian at UC Berkeley and Prof. Guillaume Baffou at Institut
Fresnel)
LBNL 2016 Director’s Award for
Exceptional Scientific Achievement
For development of SINS (Synchrotron Infrared Nano
Spectroscopy), by Hans Bechtel and Michael Martin
Hans Bechtel Michael Martin
Arthur Montazeri
2. Designing and Defining Large Macromolecular Assemblies
12 x ( + + ) =
Design
Define Conformation and Assembly with SAXS
Disassembled Trimers
at High pHCollapsed 12mer
Low Salt, Moderate pH
Expanded 12mer
High Salt, Moderate pH
Salt and pH Control
for Caging and
Release of Substrate
Collaboration between
IDAT & UCLA DOE Institute
Science Advances Dec 2016
Synthesized Recombinantly
in Microbes
3. Multiprotein Machine is Flexibly Linked to
Allow Access for DNA Double-strand Break (DSB) Repair
An Intrinsically Disordered APLF Links Ku, DNA-
PKcs and XRCC4-DNA Ligase IV in an Extended
Flexible Non-Homologous End Joining Complex.
JBC By: Hammel M et al. 2016 , Dec 30.
To examine the solution structure of NHEJ
complexes, we employed small angle X-ray
scattering (SAXS) in line with sized exclusion
chromatography (SEC-SAXS).
The architecture of the Non-Homologous End Joining
(NHEJ) complex based on combined crystallographic and
SAXS structures explains the synergy of protein
interactions for ligating DSBs.
4. Rapid Functional Analysis of NPQ-related Genes
Leonelli et al. (2016) Plant Journal 88: 375-386.
Scientific Achievement
Using transient expression in Nicotiana
benthamiana, we investigated the function of
NPQ-related genes from several organisms.
Significance and Impact
This work established a system for testing the
concept that altering expression of NPQ-
related genes can speed up NPQ kinetics and
improve photosynthesis in plants.
Research Details
– Agrobacterium cells containing constructs for
expression of NPQ-related genes were infiltrated
into mature leaves of N. benthamiana.
– Effects on NPQ were assayed using chlorophyll
fluorescence measurements.
– This method enables rapid functional testing of
genes involved in photoprotection.
Transient expression of NPQ-related
genes in leaves of N. benthamiana
affects NPQ kinetics and capacity.
Editor's Notes
Four BSISB-relevant highlights for the period of 09/2016 through 12/2016:
09/2016: “Plasmonic Graded Gratings for Hyperspectral Near-Field Infrared Sensing and Imaging” by Arthur Montazeri, Nazir Kherani, and Hoi-Ying Holman received the Best 2016 FACSS (Federation of Analytical Chemistry and Spectroscopy Societies) Poster Award at the 2016 SCIX (the great SCIentific eXchange) Conference.
10/2016: “Plasmon-assisted synthesis of ultra-precise designer-nanoparticles” prepared by Arthur Montazeri (in collaboration with Prof. Roya Maboudian at UC Berkeley and Prof. Guillaume Baffou at Institut Fresnel) was awarded the France-Berkeley Fund (FBF) that promotes scholarly exchange in all disciplines between UC Berkeley and all research centers and public institutions of higher education in France.
11/2016: Hans Bechtel and Michael Martin received the LBNL 2016 Director’s Award for Exceptional Scientific Achievement for their development of SINS (Synchrotron Infrared Nano Spectroscopy).
The complexity of large biological macromolecular assemblies enable multi-step chemistry that is difficult to accomplish by synthetic methods. However with complexity also comes entropic with challenges for coordination. At familiar scales of meters and inches one way to create stability or coordination is to use symmetric distances - all four walls of a room are a similar height for example. IDAT and UCLA/DOE institute sought to test this principle on the nanoscale with a designed hollow tetrahedron composed of 12 copies of a protein chimera. Macromolecular crystallographic (MX) results were surprising in that despite using the same building block for all edges few were in the same conformation. With SAXS we studied the solution behavior uncovering solution conditions that could manipulate conformation and assembly. We also developed novel SAXS tools to extract this information on hundreds of variants so as to design cages with custom properties.
DNA double-strand break (DSB) repair by non-homologous end joining (NHEJ) in human cells is initiated by Ku heterodimer binding to a DSB, followed by recruitment of core NHEJ factors. Small angle X-ray scattering (SAXS) and mutational analyses unveil the solution architecture of the six-protein complex and suggest cooperative assembly of an extended flexible NHEJ core complex that supports APLF accessibility while possibly providing flexible attachment of the core complex to chromatin. The resulting dynamic tethering furthermore provides geometric access of Ligase catalytic domains to the DNA ends during ligation and of kinase (DNA-PKcs) for targeted phosphorylation of other NHEJ proteins as well as trans-phosphorylation of DNA-PKcs on the opposing DSB without disrupting the core ligation complex. Overall our results shed light on evolutionary conservation of NHEJ factors activities.
One possible way to improve photosynthesis is to engineer photoprotection mechanisms (measured as non-photochemical quenching of chlorophyll a fluorescence, NPQ) to induce and relax more quickly, resulting in smaller losses under dynamic light conditions. Previous studies aimed at understanding the enzymes involved in the regulation of NPQ have relied primarily on labor-intensive and time-consuming generation of stable transgenic lines and mutant populations− approaches limited to organisms amenable to genetic manipulation and mapping. To enable rapid functional testing of NPQ-related genes from diverse organisms, we performed Agrobacterium tumefaciens-mediated transient expression assays in Nicotiana benthamiana to test if NPQ kinetics could be modified in fully expanded leaves. By expressing genes known or hypothesized to be involved in NPQ, we confirmed the viability of this method for studying dynamic photosynthetic processes.
