Biochemical characterization of the 49 kDa penicillin-binding protein of Mycobacterium smegmatis

The 49 kDa penicillin-binding protein (PBP) of Mycobacterium smegmatis catalyses the hydrolysis of the peptide or S-ester bond of carbonyl donors R1-CONH-CHR2-COX-CHR3-COO- (where X is NH or S). In the presence of a suitable amino acceptor, the reaction partitions between the transpeptidation and hydrolysis pathways, with the amino acceptor behaving as a simple alternative nucleophile at the level of the acyl-enzyme. By virtue of its N-terminal sequence similarity, the 49 kDa PBP represents one of the class of monofunctional low-molecular-mass PBPs. An immunologically related protein of Mr 52000 is present in M. tuberculosis. The 49 kDa PBP is sensitive towards amoxycillin, imipenem, flomoxef and cefoxitin.

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Sequence similarity of calreticulin with a Ca2+-binding protein that co-purifies with an Ins(1,4,5)P3-sensitive Ca2+ store in HL-60 cells

Biochemical Journal ◽

10.1042/bj2700545 ◽

1990 ◽

Vol 270 (2) ◽

pp. 545-548 ◽

Cited By ~ 37

Author(s):

K H Krause ◽

H K B Simmerman ◽

L R Jones ◽

K P Campbell

Keyword(s):

Binding Protein ◽

Sequence Similarity ◽

Deae Cellulose ◽

Subcellular Fractionation ◽

Amino Acid Sequence Similarity ◽

Rabbit Muscle ◽

Related Protein ◽

Terminal Sequence ◽

Subcellular Compartment ◽

Relationship Of

HL-60 cells possess a 60 kDa Ca2(+)-binding protein that is contained in a discrete subcellular compartment, referred to as calciosomes. Subcellular fractionation studies have suggested that, in HL-60 cells, this intracellular compartment is an Ins(1,4,5)P3-sensitive Ca2+ store. In order to investigate the structural relationship of the 60 kDa Ca2(+)-binding protein of HL-60 cells to other Ca2(+)-binding proteins, we have purified the protein by ammonium sulphate extraction, acid precipitation, and DEAE-cellulose and phenyl-Sepharose column chromatography. The N-terminal sequence of the protein shows 93% identity with rabbit muscle calreticulin, a recently cloned sarcoplasmic reticulum Ca2(+)-binding protein. No amino acid sequence similarity with calsequestrin was found, although the purified protein cross-reacted with anti-calsequestrin antibodies. The calreticulin-related protein of HL-60 cells might play a role as an intravesicular Ca2(+)-binding protein of an Ins(1,4,5)P3-sensitive Ca2+ store.

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Characterization of a Mycobacterium smegmatis Mutant Lacking Penicillin Binding Protein 1

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.43.12.3011 ◽

1999 ◽

Vol 43 (12) ◽

pp. 3011-3013 ◽

Cited By ~ 26

Author(s):

Helen Billman-Jacobe ◽

Ruth E. Haites ◽

Ross L. Coppel

Keyword(s):

Mycobacterium Tuberculosis ◽

Mycobacterium Smegmatis ◽

Liquid Culture ◽

Binding Protein ◽

Mycobacterium Leprae ◽

Deficient Mutant ◽

Penicillin Binding Protein

ABSTRACT The ponA gene of Mycobacterium smegmatisencodes a 95-kDa penicillin binding protein, PBP1, that is similar to PBP1s of Mycobacterium tuberculosis and Mycobacterium leprae. Transposon disruption of ponA in M. smegmatis resulted in a PBP1-deficient mutant that was sensitive to β-lactam antibiotics, was more permeable to glycine, and grew slowly in liquid culture.

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