The amino acid sequence of the D-galactose-binding protein from Escherichia coli B/r.

W.C Mahoney,R.W Hogg,M.A Hermodson

doi:10.1016/s0021-9258(19)69441-x

Abstract

The complete primary structure of the Escherichia coli B/r galactose-binding protein was determined by the automated sequencing of fragments produced by cleavage with cyanogen bromide, o-iodosobenzoic acid, limited trypsin digestion, mild acid hydrolysis, and Staphylococcus aureus strain V8 protease. The protein, which has 309 amino acids, is notable in the extent to which it differs from the L-arabinose-binding protein. Comparison of these two proteins indicates only about 18% homology despite the close structural resemblence of the molecules which they bind. The galactose-binding protein is the chemoreceptor initiating chemotaxis toward galactose, and it thus becomes the first protein component required for chemotaxis for which the primary structure is known. GM 24602

Highlights

We present here the complete amino acid sequence of the E . coli B/r galactose-binding protein
These proteins appear to bedissolved in the periplasmic fluid or loosely associated with the membrane or peptidoglycan environment (1,4).In the several systems studied to date, nutrient transporits accomplished by the interaction of the binding protein with nutrient bound with twomembrane proteins in an energy-dependent process (4-6, 8)
This has been demonstrated most clearly by Lo (5) by isolating the binding protein and the two membrane proteins involved in the transport of dicarboxylic acids in Escherichia coli K12 and reconstituting bindingprotein-dependent transport inmouseL-cells and rat myoblasts driven by a valinomycin-inducedchemical gradient

Summary

Introduction

The protein, through direct physical contact with MCP-I1 (9), and that the which has 309 amino acids, is notable in the extent to which it differs from the L-arabinose-binding protein. We present here the complete amino acid sequence of the E . The primary structure of the E. coli B/r galactose-binding protein (Fig. 1) is the fifth complete binding protein sequence determined.

Results

Conclusion