Probing the Structural Role of an αβ Loop of Maltose-binding Protein by Mutagenesis: Heat-shock Induction by Loop Variants of the Maltose-binding Protein that Form Periplasmic Inclusion Bodies

1996 ◽  
Vol 262 (2) ◽  
pp. 140-150 ◽  
Author(s):  
Jean-Michel Betton ◽  
Didier Boscus ◽  
Dominique Missiakas ◽  
Satish Raina ◽  
Maurice Hofnung
1998 ◽  
Vol 180 (9) ◽  
pp. 2507-2514 ◽  
Author(s):  
Bryn D. Nelson ◽  
Beth Traxler

ABSTRACT The maltose transport complex of Escherichia coli is a well-studied example of an ATP-binding cassette transporter. The complex, containing one copy each of the integral membrane proteins MalG and MalF and two copies of the peripheral cytoplasmic membrane protein MalK, interacts with the periplasmic maltose-binding protein to efficiently translocate maltose and maltodextrins across the bacterial cytoplasmic membrane. To investigate the role of MalG both in MalFGK2 assembly interactions and in subsequent transport interactions, we isolated and characterized 18 different MalG mutants, each containing a 31-residue insertion in the protein. Eight insertions mapping to distinct hydrophilic regions of MalG permitted either assembly or both assembly and transport interactions to occur. In particular, we isolated two insertions mapping to extracytoplasmic (periplasmic) regions of MalG which preserved both assembly and transport abilities, suggesting that these are permissive sites in the protein. Another periplasmic insertion seems to affect only transport-specific interactions between MalG and maltose-binding protein, defining a novel class of MalG mutants. Finally, four MalG mutant proteins, although stably expressed, are unable to assemble into the MalFGK2 complex. These mutants contain insertions in only two different hydrophilic regions of MalG, consistent with the notion that a restricted number of domains in this protein are critical complex assembly determinants. These MalG mutants will allow us to further explore the intermolecular interactions of this model transporter.


2001 ◽  
Vol 23 (1) ◽  
pp. 22-32 ◽  
Author(s):  
Yves Nominé ◽  
Tutik Ristriani ◽  
Cécile Laurent ◽  
Jean-François Lefèvre ◽  
Étienne Weiss ◽  
...  

2012 ◽  
Vol 116 (14) ◽  
pp. 4255-4262 ◽  
Author(s):  
Marco Bacci ◽  
Mauro Chinappi ◽  
Carlo Massimo Casciola ◽  
Fabio Cecconi

2016 ◽  
Vol 62 (3) ◽  
pp. 377-382
Author(s):  
David S Waugh

A common problem encountered during the production of recombinant proteins, particularly in bacteria, is their tendency to accumulate in an insoluble and inactive form (i.e., as inclusion bodies). Although sometimes it is possible to convert the aggregated material into native, biologically active protein, this is a time-consuming, costly, and uncertain undertaking. Consequently, a general means of circumventing the formation of inclusion bodies is highly desirable. During the 1990s, it was serendipitously discovered that certain highly soluble proteins have the ability to enhance the solubility of their fusion partners, thereby preventing them from forming insoluble aggregates. In the ensuing years, Escherichia coli maltose-binding protein (MBP) has emerged as one of the most effective solubility enhancers. Moreover, once rendered soluble by fusion to MBP, many proteins are able to fold into their biologically active conformations. This brief review article focuses on our current understanding of what makes MBP such an effective solubility enhancer and how it facilitates the proper folding of its fusion partners.


1990 ◽  
Vol 214 (1) ◽  
pp. 337-350 ◽  
Author(s):  
Pierre Martineau ◽  
Sevec Szmelcman ◽  
John C. Spurlino ◽  
Florente A. Quiocho ◽  
Maurice Hofnung

Sign in / Sign up

Export Citation Format

Share Document