Properties and crystallization of a genetically engineered, water-soluble derivative of penicillin-binding protein 5 of Escherichia coli K12

Derivatives of the Escherichia coli penicillin-binding protein 5 (PBP5) with truncated carboxyl terminals were obtained by altering the carboxyl-coding end of the dacA gene. After cloning the modified dacA gene into a runaway-replication-control plasmid, one clone that overproduced and excreted the desired protein into the periplasm was used as a source for the isolation of a water-soluble PBP5 (i.e. PBP5S). In PBP5S the carboxyl-terminal 21-amino-acid region of the wild-type protein was replaced by a short 9-amino-acid segment. Milligram amounts of PBP5S were purified by penicillin affinity chromatography in the absence of detergents or of chaotropic agents. PBP5S was stable and possessed DD-carboxypeptidase activity without added Triton X-100. Upon reaction with [14C]benzylpenicillin it was converted into a rather short-lived acyl-enzyme complex, as observed with PBP5. Both PBP5 and PBP5S were crystallized. In contrast to PBP5, PBP5S yielded enzymatically active, well-formed prismatic crystals suitable for X-ray analysis

Interactive molecular biology computing.

It is clear that the selection of the best possible algorithm for a computer program is essential for the creation of a useful tool. After this first step is taken, however, the usefulness of such a program may be greatly enhanced or impeded by the way it is implemented. We illustrate this point by describing our implementation of the well known FASTP/FASTIN algorithm in an interactive software environment

A high speed, high capacity homology matrix: zooming through SV40 and polyoma.

We present a new homology matrix program which owes its basic conception to the two-dimensional dot matrices previously described (1,2), but has important improvements and new features. It scores sequence homology over an adjustable range and plots the scores which are above an operator-determined filtration level. Its powerful noise-filtration system, capacity for compression without much loss of information, and speed of execution make this program a valuable tool in the analysis of homologies, internal direct repeats and reverse repeats, including palindromic sequences. The properties of the program are exemplified by analysis of SV40 and polyoma DNA sequences

A convenient and adaptable package of computer programs for DNA and protein sequence management, analysis and homology determination.

We describe the further development of a widely used package of DNA/protein sequence analysis programs (1). Important revisions have been made based on user experience, and new features, multi-user capability, and a set of large scale homology programs have been added. The programs are very user friendly, economical of time and memory, and extremely transportable. They are written in a version of FORTRAN which will compile, with a few defined changes, as FORTRAN 66, FORTRAN 77, FORTRAN IV, FORTRAN IV+, and others. They are running on a variety of microcomputers, minicomputers, and mainframes, in both single user and multi-user configurations

A convenient and adaptable package of DNA sequence analysis programs for microcomputers.

We describe a package of DNA data handling and analysis programs designed for microcomputers. The package is convenient for immediate use by persons with little or no computer experience, and has been optimized by trial in our group for a year. By typing a single command, the user enters a system which asks questions or gives instructions in English. The system will enter, alter, and manage sequence files or a restriction enzyme library. It generates the reverse complement, translates, calculates codon usage, finds restriction sites, finds homologies with various degrees of mismatch, and graphs amino acid composition or base frequencies. A number of options for data handling and printing can be used to produce figures for publication. The package will be available in ANSI Standard FORTRAN for use with virtually any FORTRAN compiler