High-speed atomic force microscopy (HS-AFM) can be used to visualize function-related conformational changes of single soluble proteins. Similar studies of single membrane proteins are, however, hampered by a lack of suitable flat, non-interacting membrane supports and by high protein mobility. Here we show that streptavidin crystals grown on mica-supported lipid bilayers can be used as porous supports for membranes containing biotinylated lipids. Using SecYEG (protein translocation channel) and GlpF (aquaglyceroporin), we demonstrate that the platform can be used to tune the lateral mobility of transmembrane proteins to any value within the dynamic range accessible to HS-AFM imaging through glutaraldehyde-cross-linking of the streptavidin. This allows HS-AFM to study the conformation or docking of spatially confined proteins, which we illustrate by imaging GlpF at sub-molecular resolution and by observing the motor protein SecA binding to SecYEG.

The SecA–SecYEG complex is stable in the absence of nucleotides due to a dual recognition mechanism.

Abstract-Flexible production assistants of the future are required to be skillful, universally applicable, safe and easy to program. State of the art robot systems that are intended to be used for human robot collaboration require in some cases unintuitive text based programming, and remain, especially in combination with peripheral hardware like external sensors or machine vision algorithms, complicated. The FlexRoP project tries to overcome current limitations by development and usage of a flexible skill-based robot programming middleware and improved user interface technologies. This paper introduces usecases, the intended system architecture, methodology for description and training of kinesthetic skills as well as first application results and intentions for future developments.

16Translocation of many secretory proteins through the bacterial plasma membrane is facilitated by 17 a complex of the protein translocase SecYEG with the motor protein SecA. The ATP-free complex 18 is unstable in detergent, raising the question how SecA may perform several rounds of ATP 19 hydrolysis without being released. Here we show that dual recognition of (i) SecYEG and (ii) acidic 20 lipids in its immediate vicinity confers an apparent nanomolar affinity. As a result the complex 21 between SecA and reconstituted SecYEG may be stable for tens of seconds as visualized by high-22 27 28 29 30

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