title: Mycobacterium tuberculosis copper-regulated protein SocB is an intrinsically disordered protein that folds upon interaction with a synthetic phospholipid bilayer.
abstract: Multiple genes in Mycobacterium tuberculosis (Mtb) are regulated by copper including socAB (small orf induced by copper A and B), which is induced by copper and repressed by RicR (regulated in copper repressor). socA and socB encode hypothetical proteins of 61 and 54 amino acids, respectively. Here, we use biophysical and computational methods to evaluate the SocB structure. We find that SocB lacks evidence for secondary structure, with no thermal cooperative unfolding event, according to circular dichroism measurements. 2D NMR spectra similarly exhibit hallmarks of a disordered structural state, which is also supported by analyzing SocB diffusion. Altogether, these findings suggest that by itself SocB is intrinsically disordered. Interestingly, SocB interacts with a synthetic phospholipid bilayer and becomes helical, which suggests that it may be membrane-associated.
authors.affiliation: Protein Processing Section, Structural Biophysics Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, Maryland, 21702.
authors.forename: Urszula
authors.initials: U
authors.lastname: Nowicka
authors.affiliation: Protein Processing Section, Structural Biophysics Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, Maryland, 21702.|Middletown High School, Middletown, Maryland, 21769.
authors.forename: Morgan
authors.initials: M
authors.lastname: Hoffman
authors.affiliation: Protein Processing Section, Structural Biophysics Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, Maryland, 21702.
authors.forename: Leah
authors.initials: L
authors.lastname: Randles
authors.affiliation: Department of Microbiology, New York University School of Medicine, New York, New York, 10016.
authors.forename: Xiaoshan
authors.initials: X
authors.lastname: Shi
authors.affiliation: Synthetic Biologics Facility, Cancer and Inflammation Program, Center for Cancer Research, National Cancer Institute, Frederick, Maryland, 21702.
authors.forename: Lyuba
authors.initials: L
authors.lastname: Khavrutskii
authors.affiliation: Synthetic Biologics Facility, Cancer and Inflammation Program, Center for Cancer Research, National Cancer Institute, Frederick, Maryland, 21702.
authors.forename: Karen
authors.initials: K
authors.lastname: Stefanisko
authors.affiliation: Synthetic Biologics Facility, Cancer and Inflammation Program, Center for Cancer Research, National Cancer Institute, Frederick, Maryland, 21702.
authors.forename: Nadya I
authors.initials: NI
authors.lastname: Tarasova
authors.affiliation: Department of Microbiology, New York University School of Medicine, New York, New York, 10016.
authors.forename: K Heran
authors.initials: KH
authors.lastname: Darwin
authors.affiliation: Protein Processing Section, Structural Biophysics Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, Maryland, 21702.
authors.forename: Kylie J
authors.initials: KJ
authors.lastname: Walters
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry* / Q000378:metabolism; D003300:Copper / Q000737:chemistry* / Q000378:metabolism; D064267:Intrinsically Disordered Proteins / Q000737:chemistry* / Q000378:metabolism; D008051:Lipid Bilayers / Q000737:chemistry / Q000378:metabolism; D008565:Membrane Proteins / Q000737:chemistry* / Q000378:metabolism; D008969:Molecular Sequence Data; D009169:Mycobacterium tuberculosis / Q000201:enzymology*
chemical_list: D001426:Bacterial Proteins; D064267:Intrinsically Disordered Proteins; D008051:Lipid Bilayers; D008565:Membrane Proteins; D003300:Copper
keywords: Mycobacterium tuberculosis (Mtb); SocB; intrinsically disordered proteins; membrane protein; synthetic phospholipid bilayer