Disease relevance of malK

• The structure and expression of the distal part of the malK-lamB operon in Escherichia coli was studied [1].
• The malE and malK genes from Salmonella typhimurium, and the malEFG operon and a portion of malK from Enterobacter aerogenes were cloned and sequenced [2].
• The malK gene, encoding a membrane-associated component of the maltose transport complex of Salmonella typhimurium was cloned into an expression vector downstream of the promoters lambda pR and lambda pL and a strong translation initiation region [3].
• To demonstrate the use of this phage, we isolated lacZ fusions to the malB locus [4].

High impact information on malK

• From maltose-negative mutants of the two categories, we isolated suppressor mutations within malK that restore transport [5].
• We show here that one can successfully replace all of the CRP sites by the binding site of another DNA-bending protein, integration host factor, or by a sequence-directed bend without altering the process of malKp activation [6].
• The products of the malF, malG, and malK genes form a membrane-associated complex that catalyzes the hydrolysis of ATP to provide energy for the transport event [7].
• Three adjacent binding sites for cAMP receptor protein are involved in the activation of the divergent malEp-malKp promoters [8].
• Six malK point mutations were isolated specifically affecting the interaction with MalT, the transcriptional regulator of the maltose system [9].

Chemical compound and disease context of malK

• The malK gene of Salmonella typhimurium encoding the ATP-hydrolyzing subunit of the ATP-Binding Cassette (ABC) transporter for maltose was subcloned into the pRSET5d expression vector [10].

Biological context of malK

• A DNA sequence containing the control regions of the malEFG and malK-lamB operons in Escherichia coli K12 [11].
• It decreases the activity of malKp by at least four orders of magnitude and likely alters the MalT binding site [12].
• First, we optimized the yield in purified complex protein by taking advantage of a newly constructed expression plasmid that carries the malK, malF and malG genes in tandem orientation [13].
• Furthermore, random mutagenesis of the plasmid-borne lacK gene yielded three clones that were superior to wild-type lacK in complementing a malK mutation [14].
• DNA sequence comparison revealed that the malK gene was generated through the duplication of the mdxK gene before lateral gene transfer of the mal gene cluster from T. litoralis to Pyrococcus furiosus [15].

Associations of malK with chemical compounds

• We found that when all three genes were present or when malF and malK were present together, the corresponding antigens were detected easily on Western immunoblots and were soluble in the non-ionic detergent, Triton X-100 [16].
• To this end, single cysteine residues were introduced into each subunit at several positions and the respective malF and malG alleles were individually co-expressed with each of the malK alleles [17].
• The third class of malK mutations resulted in resistance to the enzyme IIIGlc-mediated inhibitory effects of alpha-methylglucoside [18].

Other interactions of malK

• Using the constitutive expression of a malK-lacZ fusion as a signal, we cloned the malI gene, expressed it in minicells, and determined its DNA sequence [19].
• Reconstitution of maltose transport in malB and malA mutants of Escherichia coli [20].

Analytical, diagnostic and therapeutic context of malK

• For a better insight into the role of DT3 in signal integration, we PCR mutagenized the DT3-encoding region and screened for gain of function mutations in a malK+ strain in the absence of repression by MalY or Aes [21].

References