https://www.alisemuok.net/home daily 1.0 2023-03-23 https://images.squarespace-cdn.com/content/v1/60742d9afa44b4252e4da943/1618229130703-MSUMG23O3MJJFZJA10TD/IMG_0841.JPG Home https://images.squarespace-cdn.com/content/v1/60742d9afa44b4252e4da943/1618491722864-9R40C0IOA10PFQPEQA9R/IMG-20210413-WA0000.jpg Home https://www.alisemuok.net/research daily 0.75 2021-04-16 https://images.squarespace-cdn.com/content/v1/60742d9afa44b4252e4da943/1618237786271-ML5X0HMKBNGYGHIBTJKO/Header2.jpg Research https://images.squarespace-cdn.com/content/v1/60742d9afa44b4252e4da943/1618237817028-5BY29VDBZIW0NLV54BFD/Header3.jpg Research https://images.squarespace-cdn.com/content/v1/60742d9afa44b4252e4da943/1618237875090-GSS1B0USJGOSITA3AQ0G/Header4.jpg Research https://images.squarespace-cdn.com/content/v1/60742d9afa44b4252e4da943/1618237909630-INQ5D4VLXZRXC8RYHAVB/Header5.jpg Research https://images.squarespace-cdn.com/content/v1/60742d9afa44b4252e4da943/1618563458621-W2D5I2CGX9W9POJLAGHS/Header8.jpg Research https://www.alisemuok.net/publications daily 0.75 2022-01-18 https://images.squarespace-cdn.com/content/v1/60742d9afa44b4252e4da943/74c819fd-30aa-4da9-a503-d262f007d9b4/Screen+Shot+2022-01-18+at+11.35.43.png Publications - A new chemotaxis sensor in spirochetes. Muok, A.R., Kurniyati, K., Ortega, D.R., Olsthoorn, F., Sidi Mabrouk, A., Li, C., Briegel, A. BioRxiv. 2022. In this preprint, I examine the role of an uncharacterized protein, called CheWS, in the spirochete life cycle. CheWS is a variant of the chemotaxis protein CheW that possesses an additional fused domain, which senses the small molecule S-adenosylmethionine (SAM). This domain is responsible for chemotaxis towards SAM, but also alters round body and biofilm formation. https://images.squarespace-cdn.com/content/v1/60742d9afa44b4252e4da943/1618491581643-DDCKXTJLGJRIOZX1EGZZ/Screen+Shot+2020-11-08+at+18.33.53.png Publications - Microbial hitchhike Muok, A.R., Briegel, A., and Claessen, D. ISMEJ. 2021. In this manuscript I show that immotile Streptomyces spores are able to hitchhike motile bacteria natively found in their vicinity for migration to plant tissues. Using motility assays, I show that Bacillus subtilis can move the spores to plant tissues and that this movement is dependent on the presence of flagella. Through various electron microscopy methods, I show that the flagella interact with the rodlet layer found on the spore coat. I used genetic mutants to confirm the importance of the rodlet layer for this interaction. https://images.squarespace-cdn.com/content/v1/60742d9afa44b4252e4da943/1618241355137-OZ1FUSM43QRLAB0UXM6Y/Screen+Shot+2021-04-12+at+17.28.33.png Publications - A new chemotaxis array symmetry Muok et al. Nat Comms. 2020. While the bacterial chemotaxis system has been studied for several decades in very diverse bacteria, all bacteria were found to possess a pseudo-P6 symmetry in the array. Here, for the first time, I show an alternative (P2) symmetry of the arrays, which are in pathogenic Spirochetes. This manuscript showcases how cryo-ET coupled with crystallography and biochemistry can synergistically answer questions across biological scales. https://images.squarespace-cdn.com/content/v1/60742d9afa44b4252e4da943/1618493298515-9KKTJHCFZO28HVULVI6A/scisig.gif Publications - Trapping CheA transitions Muok et al. Sci. Signal. 2020. The kinase CheA is essential for chemotatic function. For some pathogenic microbes, deletion of CheA inhibits host infection. However, this protein is highly dynamic and various conformations have been associated with specific sensory states of the chemotaxis apparatus. Here, I apply structural and biochemical methods to elucidate a complete all-atom model for the kinase-inactive signalling state. To accomplish this, I first engineered a chimeric, soluble chemotaxis complex that enables further in vitro exploration into this system. This paper was also chosen for the cover story of this issue! https://images.squarespace-cdn.com/content/v1/60742d9afa44b4252e4da943/1618240520816-17WW7CTWU536AC0YQBFP/Screen+Shot+2020-09-13+at+22.28.25.png Publications - A Hitchhiker’s Guide Muok, A.R. and Briegel, A. Trends Microbiol. 2020 In this first-ever review of intermicrobial hitchhiking, I examine reports of hitchhiking in both prokaryotes and eukaryotes. After drawing out the similarities and differences among them, I make important connections to their potential impacts on plant and human health. Best of all, Ariane Briegel and I hand-painted the key figure for this review. https://images.squarespace-cdn.com/content/v1/60742d9afa44b4252e4da943/1618492595479-INFV8U0Q0N6R8Z0T1HDR/Screen+Shot+2021-04-15+at+15.16.00.png Publications - A new class of chemotaxis sensor Muok et al. PNAS. 2019. Typically, the chemotaxis system consists of three proteins that comprise the main structure of chemotaxis arrays. However, some organisms, such as pathogenic Spirochetes, possess uncharacterized chemotaxis proteins. Here, I use structural, biochemical, and spectroscopic methods to characterize one such protein, which I have named Oxygen Diiron Protien (ODP). I found that ODP is an oxygen sensor that modulates chemotaxis behavior via an iron-peroxy adduct. https://images.squarespace-cdn.com/content/v1/60742d9afa44b4252e4da943/1618492793649-2RUQ220GF9212QGMHNEH/drawingArrays.jpg Publications - CheA: making sense of it all Muok, A.R., Briegel, A., and Crane, B.C. BBA-Biomem. 2019. The chemotaxis kinase CheA undergoes dramatic structural rearrangements between the kinase-on and kinase-off state. Here, I consolidate structural and enzymatic reports of CheA, and use this information to generate a model for CheA in both activity states. https://images.squarespace-cdn.com/content/v1/60742d9afa44b4252e4da943/1618553560211-QIGSZKY8WTQBELOGO61T/Screen+Shot+2021-04-16+at+08.12.06.png Publications https://www.alisemuok.net/activities daily 0.75 2021-04-17 https://images.squarespace-cdn.com/content/v1/60742d9afa44b4252e4da943/1618578219283-W3T4BIAO7ZSYEHO3K3CR/auto.jpeg Activities https://images.squarespace-cdn.com/content/v1/60742d9afa44b4252e4da943/1618572238141-9JLV0V4LQCJ6410HTA36/Screen+Shot+2021-04-16+at+13.19.11.png Activities - BLAST XVI The Bacterial Locomotion and Signal Transduction (BLAST) conference takes place every two years, and at a new location almost every time! But due to the coronavirus pandemic, we of course had to opt for an online format this year. Despite not seeing my friends face-to-face, this years conference was incredibly fun! I had the honor of helping organize the social media component of the conference, which was a great new experience, and I gave a talk about my project with Streptomyces spore transport. Best of all, this year there was a SciArt component of the conference, where every speaker had three artists make a piece inspired by their talk. One of the artists I had was Dr. Lizah van der Aart who made the amazing illustration shown here. I love the comic style of the art she made, which brings out the dynamics of the system. Lizah makes all kinds of science-inspired art and you can find it on her etsy shop here. https://images.squarespace-cdn.com/content/v1/60742d9afa44b4252e4da943/1618572920482-UNX2IA9NESZXXZWSWXF4/Screen+Shot+2021-04-16+at+13.33.46.png Activities - I hope that the next Gordon Research Conference: Sensory Transduction in Microorganisms will be able to take place in-person in January 2022. Since my first STIM conference in 2014, I have gone to every single one. It’s also been several years since I’ve gotten to see many friends and collaborators. The location is set in Ventura, California in a beach hotel so I’m sure everyone else is hoping to be there too! The 2020 GRC STIM conference and all its attendees —> https://images.squarespace-cdn.com/content/v1/60742d9afa44b4252e4da943/1618574640054-TDALQQ1G1P99SMCS06GZ/Screen+Shot+2021-04-16+at+14.02.00.png Activities - The best part of the GRC STIM is getting to spend time with everyone outside. Even though it takes place in January, it’s always warm and sunny. Pictures from STIM 2020, like this one with Ariane Briegel, make me excited for what’s to come! https://www.alisemuok.net/pagecv daily 0.75 2021-04-16 https://www.alisemuok.net/sci-art daily 0.75 2021-04-16 https://images.squarespace-cdn.com/content/v1/60742d9afa44b4252e4da943/1618569481693-NO3JTT42CBI2ZDCB4TE1/20201216_153053.jpg Sci Art https://images.squarespace-cdn.com/content/v1/60742d9afa44b4252e4da943/1618569421399-J8008PVSOLG4P8X8QUKG/LorealFigure.jpg Sci Art https://images.squarespace-cdn.com/content/v1/60742d9afa44b4252e4da943/1618569123457-3KN13V1AZK1FW1NHFAB5/final3.jpg Sci Art https://images.squarespace-cdn.com/content/v1/60742d9afa44b4252e4da943/1618569222103-OSLI3VATT7BEOYF65IGV/Screen+Shot+2021-04-16+at+12.15.47.png Sci Art https://images.squarespace-cdn.com/content/v1/60742d9afa44b4252e4da943/1618569638501-B4QBG80M0NUOBD141S5J/Screen+Shot+2020-09-13+at+22.28.25.png Sci Art https://images.squarespace-cdn.com/content/v1/60742d9afa44b4252e4da943/1618569872636-10YZ04WY9OSRP94JORVL/drawingArrays.jpg Sci Art https://images.squarespace-cdn.com/content/v1/60742d9afa44b4252e4da943/1618569790408-NAHBPGCVEL9SR09CRMN9/Header.jpg Sci Art https://images.squarespace-cdn.com/content/v1/60742d9afa44b4252e4da943/1618570942271-D9CTQ3R4PKDA9YYE8EFA/Screen+Shot+2021-04-16+at+13.01.45.png Sci Art