@article {8674, title = {Cryo-EM structure of the mycobacterial 70S ribosome in complex with ribosome hibernation promotion factor RafH [National Cryo-EM Facility, BLiSC]}, journal = {Nat Commun}, volume = {15}, year = {2024}, month = {2024 Jan 20}, pages = {638}, abstract = {

Ribosome hibernation is a key survival strategy bacteria adopt under environmental stress, where a protein, hibernation promotion factor (HPF), transitorily inactivates the ribosome. Mycobacterium tuberculosis encounters hypoxia (low oxygen) as a major stress in the host macrophages, and upregulates the expression of RafH protein, which is crucial for its survival. The RafH, a dual domain HPF, an orthologue of bacterial long HPF (HPF), hibernates ribosome in 70S monosome form, whereas in other bacteria, the HPF induces 70S ribosome dimerization and hibernates its ribosome in 100S disome form. Here, we report the cryo- EM structure of M. smegmatis, a close homolog of M. tuberculosis, 70S ribosome in complex with the RafH factor at an overall 2.8 {\r A} resolution. The N- terminus domain (NTD) of RafH binds to the decoding center, similarly to HPF NTD. In contrast, the C- terminus domain (CTD) of RafH, which is larger than the HPF CTD, binds to a distinct site at the platform binding center of the ribosomal small subunit. The two domain-connecting linker regions, which remain mostly disordered in earlier reported HPF structures, interact mainly with the anti-Shine Dalgarno sequence of the 16S rRNA.

}, keywords = {Bacterial Proteins, Mycobacterium tuberculosis, Ribosomal Proteins, Ribosomes, RNA, Ribosomal, 16S}, issn = {2041-1723}, doi = {10.1038/s41467-024-44879-y}, author = {Kumar, Niraj and Sharma, Shivani and Kaushal, Prem S} } @article {458, title = {Proteomics and Metabolomics Analyses to Elucidate the Desulfurization Pathway of Chelatococcus sp.[Mass Spectrometry]}, journal = {PLoS One}, volume = {11}, year = {2016}, month = {2016}, pages = {e0153547}, abstract = {

Desulfurization of dibenzothiophene (DBT) and alkylated DBT derivatives present in transport fuel through specific cleavage of carbon-sulfur (C-S) bonds by a newly isolated bacterium Chelatococcus sp. is reported for the first time. Gas chromatography-mass spectrometry (GC-MS) analysis of the products of DBT degradation by Chelatococcus sp. showed the transient formation of 2-hydroxybiphenyl (2-HBP) which was subsequently converted to 2-methoxybiphenyl (2-MBP) by methylation at the hydroxyl group of 2-HBP. The relative ratio of 2-HBP and 2-MBP formed after 96 h of bacterial growth was determined at 4:1 suggesting partial conversion of 2-HBP or rapid degradation of 2-MBP. Nevertheless, the enzyme involved in this conversion process remains to be identified. This production of 2-MBP rather than 2-HBP from DBT desulfurization has a significant metabolic advantage for enhancing the growth and sulfur utilization from DBT by Chelatococcus sp. and it also reduces the environmental pollution by 2-HBP. Furthermore, desulfurization of DBT derivatives such as 4-M-DBT and 4, 6-DM-DBT by Chelatococcus sp. resulted in formation of 2-hydroxy-3-methyl-biphenyl and 2-hydroxy -3, 3/- dimethyl-biphenyl, respectively as end product. The GC and X-ray fluorescence studies revealed that Chelatococcus sp. after 24 h of treatment at 37{\textdegree}C reduced the total sulfur content of diesel fuel by 12\% by per gram resting cells, without compromising the quality of fuel. The LC-MS/MS analysis of tryptic digested intracellular proteins of Chelatococcus sp. when grown in DBT demonstrated the biosynthesis of 4S pathway desulfurizing enzymes viz. monoxygenases (DszC, DszA), desulfinase (DszB), and an NADH-dependent flavin reductase (DszD). Besides, several other intracellular proteins of Chelatococcus sp. having diverse biological functions were also identified by LC-MS/MS analysis. Many of these enzymes are directly involved with desulfurization process whereas the other enzymes/proteins support growth of bacteria at an expense of DBT. These combined results suggest that Chelatococcus sp. prefers sulfur-specific extended 4S pathway for deep-desulphurization which may have an advantage for its intended future application as a promising biodesulfurizing agent.

}, keywords = {Air Pollutants, Bacterial Proteins, Beijerinckiaceae, Gas Chromatography-Mass Spectrometry, Gasoline, Metabolomics, Phylogeny, Proteomics, Signal Transduction, Sulfur}, issn = {1932-6203}, doi = {10.1371/journal.pone.0153547}, author = {Bordoloi, Naba K and Bhagowati, Pabitra and Chaudhuri, Mihir K and Mukherjee, Ashis K} } @article {494, title = {Draft genome sequence of Staphylococcus aureus ST672, an emerging disease clone from India. [Next Generation Genomics facility]}, journal = {J Bacteriol}, volume = {194}, year = {2012}, month = {2012 Dec}, pages = {6946-7}, abstract = {

We report the draft genome sequence of methicillin-resistant Staphylococcus aureus (MRSA) strain ST672, an emerging disease clone in India, from a septicemia patient. The genome size is about 2.82 Mb with 2,485 open reading frames (ORFs). The staphylococcal cassette chromosome mec (SCCmec) element (type V) and immune evasion cluster appear to be different from those of strain ST772 on preliminary examination.

}, keywords = {Bacteremia, Bacterial Proteins, Bacterial Typing Techniques, Base Sequence, DNA, Bacterial, Genome, Bacterial, Humans, Methicillin-Resistant Staphylococcus aureus, Molecular Sequence Data, Open Reading Frames, Penicillin-Binding Proteins, Sequence Analysis, DNA, Staphylococcal Infections}, issn = {1098-5530}, doi = {10.1128/JB.01868-12}, author = {Khedkar, Supriya and Prabhakara, Sushma and Loganathan, Ramya Malarini and S, Chandana and Gowda, Malali and Arakere, Gayathri and Seshasayee, Aswin Sai Narain} }