Structural analysis of the starfish SALMFamide neuropeptides S1 and S2: The N-terminal region of S2 facilitates self-association

The 191-residue-long LrtA protein of Synechocystis sp. PCC 6803 is involved in post-stress survival and in stabilizing 70S ribosomal particles. It belongs to the hibernating promoting factor (HPF) family, intervening in protein synthesis. The protein consists of two domains: The N-terminal region (N-LrtA, residues 1101), which is common to all the members of the HPF, and seems to be well-folded; and the C-terminal region (C-LrtA, residues 102-191), which is hypothesized to be disordered. In this work, we studied the conformational preferences of isolated C-LrtA in solution. The protein was disordered, as shown by computational modelling, 1D-1H NMR, steady-state far- UV circular dichroism (CD) and chemical and thermal denaturations followed by fluorescence and far-UV CD. Moreover, at physiological conditions, as indicated by several biochemical and hydrodynamic techniques, isolated C-LrtA intervened in a self-association equilibrium, involving several oligomerization reactions. Thus, C-LrtA was an oligomeric disordered protein.

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Structural Analysis of the C-Terminal Region (Modules 18–20) of Complement Regulator Factor H (FH)

PLoS ONE ◽

10.1371/journal.pone.0032187 ◽

2012 ◽

Vol 7 (2) ◽

pp. e32187 ◽

Cited By ~ 29

Author(s):

Hugh P. Morgan ◽

Haydyn D. T. Mertens ◽

Mara Guariento ◽

Christoph Q. Schmidt ◽

Dinesh C. Soares ◽

...

Keyword(s):

Structural Analysis ◽

Factor H ◽

Terminal Region ◽

Complement Regulator

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The Dahlia mosaic virus gene VI product N-terminal region is involved in self-association

Virus Research ◽

10.1016/j.virusres.2011.04.026 ◽

2011 ◽

Vol 159 (1) ◽

pp. 69-72 ◽

Cited By ~ 5

Author(s):

Gaurav Raikhy ◽

Charles Krause ◽

Scott Leisner

Keyword(s):

Mosaic Virus ◽

Terminal Region ◽

Virus Gene ◽

Dahlia Mosaic Virus ◽

Self Association

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Salmonella enterica Serovar Paratyphi C Carries an Inactive Shufflon

Infection and Immunity ◽

10.1128/iai.72.1.22-28.2004 ◽

2004 ◽

Vol 72 (1) ◽

pp. 22-28 ◽

Cited By ~ 10

Author(s):

Connie K. P. Tam ◽

Jim Hackett ◽

Christina Morris

Keyword(s):

Typhoid Fever ◽

Base Pair ◽

Salmonella Enterica ◽

Enteric Fever ◽

Terminal Region ◽

Inverted Repeats ◽

Single Base ◽

Single Base Pair ◽

Self Association ◽

Base Pair Insertion

ABSTRACT Salmonella enterica serovar Typhi uses type IVB pili to facilitate bacterial self-association, but only when the PilV proteins (potential minor pilus proteins) are not synthesized. This pilus-mediated event may be important in typhoid fever pathogenesis. We initially show that S. enterica serovar Paratyphi C strains harbor a pil operon very similar to that of serovar Typhi. An important difference, however, is located in the shufflon which concludes the pil operon. In serovar Typhi, the Rci recombinase acts upon two 19-bp inverted repeats to invert the terminal region of the pilV gene, thereby disrupting PilV synthesis and permitting bacterial self-association. In serovar Paratyphi C, however, the shufflon is essentially inactive because each of the Rci 19-bp substrates has acquired a single base pair insertion. A PilV protein is thus synthesized whenever the pil operon is active, and bacterial self-association therefore does not occur in serovar Paratyphi C. The data thus suggest that serovar Typhi bacterial self-association using type IVB pili may be important in the pathogenesis of epidemic enteric fever.

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Structural studies of reelin N-terminal region provides insights into a unique structural arrangement and functional multimerization

The Journal of Biochemistry ◽

10.1093/jb/mvaa144 ◽

2020 ◽

Author(s):

Masamichi Nagae ◽

Kei Suzuki ◽

Norihisa Yasui ◽

Terukazu Nogi ◽

Takao Kohno ◽

...

Keyword(s):

Domain Architecture ◽

Terminal Region ◽

Adult Brain ◽

Structural Studies ◽

Irregular Domain ◽

Inhibitory Antibody ◽

Brain Functions ◽

Irregular Region ◽

Self Association ◽

Embryonic Brain Development

Abstract The large, secreted glycoprotein reelin regulates embryonic brain development as well as adult brain functions. Although reelin binds to its receptors via its central part, the N-terminal region directs multimer formation and is critical for efficient signal transduction. In fact, the inhibitory antibody CR-50 interacts with the N-terminal region and prevents higher-order multimerization and signaling. Reelin is a multidomain protein in which the central part is composed of eight characteristic repeats, named reelin repeats, each of which is further divided by insertion of an EGF module into two subrepeats. In contrast, the N-terminal region shows unique “irregular” domain architecture since it comprises three consecutive subrepeats without the intervening EGF module. Here we determined the crystal structure of the murine reelin fragment named RX-R1 including the irregular region and the first reelin repeat at 2.0 Å resolution. The overall structure of RX-R1 has a branched Y-shaped form. Interestingly, two incomplete subrepeats cooperatively form one entire subrepeat structure, though an additional subrepeat is inserted between them. We further reveal that Arg335 of RX-R1 is crucial for binding CR-50. A possible self-association mechanism via the N-terminal region is proposed based on our results.

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Self-Association of Lymphocytic Choriomeningitis Virus Nucleoprotein Is Mediated by Its N-Terminal Region and Is Not Required for Its Anti-Interferon Function

Journal of Virology ◽

10.1128/jvi.05503-11 ◽

2012 ◽

Vol 86 (6) ◽

pp. 3307-3317 ◽

Cited By ~ 25

Author(s):

E. Ortiz-Riano ◽

B. Y. H. Cheng ◽

J. C. de la Torre ◽

L. Martinez-Sobrido

Keyword(s):

Lymphocytic Choriomeningitis ◽

Lymphocytic Choriomeningitis Virus ◽

Terminal Region ◽

Self Association

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Interactions of FliJ with the Salmonella Type III Flagellar Export Apparatus

Journal of Bacteriology ◽

10.1128/jb.185.18.5546-5554.2003 ◽

2003 ◽

Vol 185 (18) ◽

pp. 5546-5554 ◽

Cited By ~ 46

Author(s):

Gillian M. Fraser ◽

Bertha González-Pedrajo ◽

Jeremy R. H. Tame ◽

Robert M. Macnab

Keyword(s):

Amino Acid ◽

Molecular Mass ◽

Analytical Ultracentrifugation ◽

Terminal Region ◽

Dominant Negative ◽

Negative Regulator ◽

Size Exclusion ◽

Dominant Negative Effect ◽

Type Iii ◽

Self Association

ABSTRACT FliJ, a 17-kDa protein, is a soluble component of the Salmonella type III flagellar protein export system that has antiaggregation properties and several other characteristics that suggest it may have a chaperone-like function. We have now examined this protein in detail. Ten-amino-acid scanning deletions covering the entire 147-amino-acid sequence were tested for complementation of a fliJ null strain; only the first and last deletions complemented. A few of the deletions, especially towards the C terminus, exerted a dominant negative effect on wild-type cells, indicating that they were actively interfering with function. Two truncated versions of FliJ, representing its N- and C-terminal halves, failed to complement and were not dominant. We tested for FliJ self-association by several techniques. Size-exclusion chromatography (Superdex 200) indicated an apparent molecular mass of around 50 kDa, which could reflect either multimerization or an elongated shape or both. Multiangle light scattering gave a peak value of 20 kDa, close to the molecular mass of the monomer. Analytical ultracentrifugation gave evidence for weak self-association as a trimer or tetramer. It was known from previous studies that FliJ interacts with the N-terminal region of FliH, a negative regulator of the ATPase FliI. Using both truncation and deletion versions of FliJ, we now show that it is its C-terminal region that is responsible for this interaction. We also show that FliJ interacts with the soluble cytoplasmic domain of the largest membrane component of the export apparatus, FlhA; although small deletions in FliJ did not interfere with the association, both truncated versions failed to associate, indicating that a substantial amount of the central region of the FliJ sequence participates in the association. We present a model summarizing these multiple interactions.

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