Fig. 6.

A. Crystal structure of STAS domain from E. coli SulP protein YchM (red) in complex with acyl carrier protein (ACP, cyan), as described by [31]. Shown in yellow is the malonyl-4'-phosphopantheine prosthetic group covalently linked through the phosphate to the hydroxyl group of conserved S36 of ACP. The structure (PDB:3NY7) was rendered in PyMOL. B. Experimental evidence supports the existence of numerous YchM-interacting proteins, grouped here by function (reproduced from [31]). C. Schematic model of YchM as a bicarbonate transporter delivering substrate to STAS domain-bound ACP for sequential transfer to multiple components of the fatty acid biosynthesis pathway assembled around the STAS-ACP complex (reproduced from [31]).