New insights into protein-DNA interactions reveal cellular machinery secrets via @physorg_com.

@m_j_ag @DrJoshRamsay @CharlieBondXray @CurtinMRI @SMS_UWA

A big thank you to fellow authors: Mark @m_j_ag, Karina Yui Eto and Drew Hall, and especially to my PhD supervisors @DrJoshRamsay and @CharlieBondXray! A big collaboration between @CurtinMRI and @SMS_UWA 👏🥳.

That brings me back to the paper. We describe how RdfS structurally controls ICE transcription, excision and transfer, all through something called “indirect readout”. Some extraordinary complexity by one little DNA-binding protein! 13/13

Sure enough, working with Mark (@m_j_ag) to do molecular dynamics, we showed RdfS DNA-binding mimicked BldC in many ways. At the same time, we did a bunch of DNA-binding and reporter assays, and showed RdfS binds different DNA targets to do different things. 12/13.

More clues, but still no full answers. We did see that another, very similar RdfS-like protein, called BldC, also had very similar characteristics when sticking to DNA. We wondered if RdfS was behaving the same way? 11/13

The next big discovery from my PhD was solving the structure of RdfS. We discovered RdfS was not all as it seemed – it liked to join up together and form big, helical structures – which looked a lot like DNA! 10/13

We wanted to know how RdfS was working to seemingly control excision, transfer and gene regulation to dictate how these ICEs moved between bacteria. We worked with structural biologist and biophysicist @CharlieBondXray to look at things at the atomic level! 9/13.

Around the same time, Josh was working with @MurdochUni’s Legume Rhizobium Sciences on another type of important “tripartite ICE”, and discovered that RdfS also regulated other genes, another clue! 8/13

Weirdly, though, we saw that when we replaced RdfS after deleting it (called complementation), only some of its roles were restored. It seems the amount of RdfS present (its concentration) was important for all the RdfS functions! 7/13.

My first PhD paper confirmed some things Josh (and others) saw. The RdfS protein was also seemingly regulating conjugation – how bacterial DNA is actually transferred between each other. 6/13

Something funny was happening with this RdfS protein though – it seemingly also did a bunch of other stuff that most of these types of proteins didn’t! That’s where I came in – about 25 years (and a few other scientists) after the discovery of ICEs in Mesorhizobia. 5/13.

Josh discovered RdfS – a “recombination directionality factor”, a small DNA-binding protein that works with other proteins to mediate cutting-out the DNA (excision) from the bacterial chromosome. 4/13

Fast forward a few years, and while @DrJoshRamsay was doing his PhD, he wanted to know how these symbiosis islands were moving on a molecular level. How do these N-fixing ICEs transfer between the Mesorhizobia bacteria, and what controls it all? 3/13.

About 30 years ago, @clive_ronson discovered that the nitrogen-fixing bacteria he was working on could share their N-fixation genes! This “symbiosis island” was a special type of chromosomally-integrated mobile element called an “ICE”. 2/13

I’m excited to finally share our work published in @NAR_Open! This is the final paper from my PhD – showing how my focal research protein RdfS uniquely coordinates a bunch of different molecular roles. Read along to get the whole story! 👀👇1/13

RT @CallumVerdonk: The @theCCDM KC Tan presenting all about regulation of necrotrophic #effectors in #fungal #wheat pathogen P. nodorum at….

The @theCCDM KC Tan presenting all about regulation of necrotrophic #effectors in #fungal #wheat pathogen P. nodorum at ECFG17 in Dublin, IRE 🍄💪💣🌾 #ecfg17 #plantpathology

RT @karchuntan: See you at @ECFG17Dublin #ECFG17! 🫡.

RT @karchuntan: Congrats to Isobel Screaigh🎓, our @theCCDM.@CHIRI_curtin Honours student got her project on fungal signal transduction done….