Identifying the prevalence and characteristics of diversity, equity, and inclusion leaders in academic emergency medicine.

Objectives: Our study aims to better understand and describe the current state of diversity, equity, and inclusion (DEI) leadership in emergency medicine (EM) by identifying the prevalence of department DEI leadership positions, their demographics, and their job duty characteristics. Methods: We disseminated an electronic survey from April to July 2022 to Society for Academic Emergency Medicine (SAEM) Association of Academic Chairs of Emergency Medicine, Academy for Diversity and Inclusion in Emergency Medicine, and the Equity and Inclusion Committee to identify department DEI leads. From July to August 2022, a 45-question survey was sent to all identified DEI leaders on individual characteristics, DEI experience, and DEI lead job description. Results: We received a response from 79 out of 120 academic EM departments identified (65.8%). Of the responding institutions, 59 (74.7%) reported a DEI leader. A total of 74.6% of these DEI leaders responded at least partially to our survey and 57.6% responded in full. The most common titles were vice/associate chair of DEI (34.4%), director of DEI (28.1%), and DEI committee chair (18.8%). Most respondents (84.4%) were the inaugural DEI lead in their department and 84.4% of respondents did not have a formal DEI role in their department previously. On average, respondents have had their DEI title for 2 years (range 0-7 years) with an average of 7 years (range 0-30 years) of experience performing DEI work. Many (63.4%) do not receive any funded effort for their DEI roles. Most DEI leads were not tenure track (72.2%) and most commonly at the rank of assistant professor (47.2%) followed by associate professor (33.3%), full professor (16.7%), and instructor (2.8%). Conclusions: This is the first known study to assess the characteristics of DEI department leaders in EM. EM DEI leadership positions are new, common, and led by diverse personal identities and are often not funded. Future directions could gain qualitative insight into this workforce to guide best practices in EM DEI leadership.

RecF protein targeting to postreplication (daughter strand) gaps I: DNA binding by RecF and RecFR.

In bacteria, the repair of post-replication gaps by homologous recombination requires the action of the recombination mediator proteins RecF, RecO and RecR. Whereas the role of the RecOR proteins to displace the single strand binding protein (SSB) and facilitate RecA loading is clear, how RecF mediates targeting of the system to appropriate sites remains enigmatic. The most prominent hypothesis relies on specific RecF binding to gap ends. To test this idea, we present a detailed examination of RecF and RecFR binding to more than 40 DNA substrates of varying length and structure. Neither RecF nor the RecFR complex exhibited specific DNA binding that can explain the targeting of RecF(R) to post-replication gaps. RecF(R) bound to dsDNA and ssDNA of sufficient length with similar facility. DNA binding was highly ATP-dependent. Most measured Kd values fell into a range of 60-180 nM. The addition of ssDNA extensions on duplex substrates to mimic gap ends or CPD lesions produces only subtle increases or decreases in RecF(R) affinity. Significant RecFR binding cooperativity was evident with many DNA substrates. The results indicate that RecF or RecFR targeting to post-replication gaps must rely on factors not yet identified, perhaps involving interactions with additional proteins.

RecFOR epistasis group: RecF and RecO have distinct localizations and functions in Escherichia coli.

In bacteria, genetic recombination is a major mechanism for DNA repair. The RecF, RecO and RecR proteins are proposed to initiate recombination by loading the RecA recombinase onto DNA. However, the biophysical mechanisms underlying this process remain poorly understood. Here, we used genetics and single-molecule fluorescence microscopy to investigate whether RecF and RecO function together, or separately, in live Escherichia coli cells. We identified conditions in which RecF and RecO functions are genetically separable. Single-molecule imaging revealed key differences in the spatiotemporal behaviours of RecF and RecO. RecF foci frequently colocalize with replisome markers. In response to DNA damage, colocalization increases and RecF dimerizes. The majority of RecF foci are dependent on RecR. Conversely, RecO foci occur infrequently, rarely colocalize with replisomes or RecF and are largely independent of RecR. In response to DNA damage, RecO foci appeared to spatially redistribute, occupying a region close to the cell membrane. These observations indicate that RecF and RecO have distinct functions in the DNA damage response. The observed localization of RecF to the replisome supports the notion that RecF helps to maintain active DNA replication in cells carrying DNA damage.