# ADD, EXP, EXPAND

NAME
ADD, EXP, EXPAND - add specified atoms to current selection.
SYNOPSIS
ADD chain_identifiers/residue_serials/residue_names/atom_names
ADD residue_ranges
ADD residue_names
ADD ATO atomic_ranges
ADD ATOMS atomic_ranges
ADD keyword
ADD ELE chemical_symbol
ADD ELEMENT chemical_symbol
DESCRIPTION
Add specified atoms to current selection. Atoms are added according to the specified cryteria. The command EXPAND does exactly the same job as ADD. The essential difference between ADD and SELECT is that ADD does not overwrite the previous selection. Four types of selection are available:
(1) detailed selection;
(2) selection by residue serial numbers;
(3) selection by residue names;
(4) special selection (by keyword);
(5) selection by chemical symbol;
(6) selection by atom serial number.
DETAILED SELECTION
In this case four data types are specified simultaneously: chain identifiers, residue serial numbers, residue names and atom names. It is not possible to specify atomic serial numbers. The selection string should contain exactly three slashes, separating different data types:
chain_identifiers/residue_serials/residue_names/atom_names.
Both uppercase and lowercase characters are accepted. Space ( ), comma (,) and semicolon (;) may be used as separators.
Chain identifiers are single alphabetic characters. Asterisk (*) may be used to select all chains. The keyword EXC (EXCEPT) may be used to exclude one or more chains from selection.
Residue serial numbers consist of digits. Minus may be used to specify a range of residue serial numbers. For example, 1-100 specifyes residues from 1 to 100, including these two. Asterisk (*) may be used to specify all residue serials. The keyword EXC (EXCEPT) may be used to exclude serial numbers or ranges from selection.
Residue names are expected in three letters code. Asterisk (*) may be used to specify all residue names. The keyword EXC (EXCEPT) may be used to exclude one or more names from selection. Non-standard names are accepted.
The names of atoms are expected as used in the input file; do not replace them with pure chemical symbols. C alpha, for example, should be specified as CA or ca (case is not important), if coordinates are read from PDB file. Asterisk (*) may be used to select all atoms, while EXC may be used to exclude some atoms from selection. Examples:

add a/*/*/* | Add all atoms from chain A to current selection.
add * exc m/*/*/ca | Add CA atoms from all chains except chain M.
add */*/*/* exc ca,c,n,o | Add all atoms except CA, C, N and O.
add a/* exc 72-112/*/ca | Add CA atoms from chain A, but exclude residues from 72 to 112.

SELECTION BY RESIDUE SERIAL NUMBERS
To select all atoms in a single residue, a residue range or in a number of residues and residue ranges, a simple syntax may be used. The selection string should contain no slashes. Keyword EXC (EXCEPT) is accepted, but asterisk (*) will be missintepreted. Minus may be used to specify residue ranges. Comma (,), semicolon (;) and space ( ) may be used as separators. Examples:

add 1-100 | Add residues from 1 to 100 to current selection.
add 1-100 exc 20-40 | Add residues 1-100 but exclude 20-40.
add 1, 4, 8, 11-48 exc 20-32 | Add residues 1, 4, 8 and 11-48 but exclude 20-32.

SELECTION BY ATOMIC SERIAL NUMBERS
To add a single atom by the atomic serial number, combine the command ADD and the keyword ATO (ATOMS). For example, to add the atom number 102 to the current selection type:
add ato 102
The same keyword may be used to add a range of atoms or to add two or more ranges. Examples:

add ato 1-100 | Add atoms which have serial numbers in the range between 1 and 100.
add 1-20 40-50 | Add atoms which have serial numbers between 1 and 20 and between 40 and 50.

Do not combine the keywords EXC (EXCLUDE) and ATO (ATOMS).
SELECTION BY RESIDUE NAMES
Three letters code should be used. Asterisk (*) and keyword EXC (EXCEPT) are not accepted. Example:

add phe,tyr,trp | Add PHE, TYR and TRP to current selection.

SPECIAL SELECTION KEYWORDS
Some special keywords may be combined with ADD to select residues or atoms according to some properties. It is also possible to select the complement, i.e. all atoms which were not selected previously. A single keyword should be used; asterisk (*) and keyword EXC (EXCEPT) are not accepted.

add * add all | Add all atoms to current selection, i.e. select all.
add abo add above | Add atoms above the plane.
add aci add acidic | Add acidic amino acids (GLU and ASP).
add ali add aliphatic | Add aliphatic amino acids (ILE, LEU and VAL).
add alt | Add atoms at alternate positions.
add bad | Add bad residues. A residue is treated as bad if the peptide bond assigned to this residue is non-planar. The peptide bond is non-planar if the omega angle is different for 20 or more degrees from 0 or 180 degrees.
add bas add basic | Add basic amino acids (ARG, LYS and HIS).
add bel add below | Add atoms below the plane.
add cha add charged | Add charged amino acids (ARG, LYS, HIS, GLU and ASP).
add cis | Add cis residues.
add com add complement | Add atoms which were not select previously.
add het add hetero | Add hetero atoms (heme groups, water etc.).
add pho add hydrophobic | Add hydrophobic amino acids (ALA, ILE, LEU, MET, PHE, TRP, VAL, TYR, CYS, GLY and HIS).
add mai add main_chain | Add main chain atoms (CA, C, N and O).
add mod serial_number add model serial_number | Add model specified by serial_number. NMR structure is a set of models. Example: add mod 1
add neg add negative | Add negatively charged amino acids (GLU and ASP).
add pat add pattern | Add the sequence pattern. The command PAT (PATTERN) is used to define the sequence pattern.
add pol add polar | Add polar amino acids (ARG, LYS, HIS, ASP, GLU, ASN, GLN, SER, THR, TRP and TYR).
add pos add positive | Add positively charged amino acids (ARG, LYS and HIS).
add seq add sequence | Add sequence fragments which match the sequence stored to the sequence buffer. The sequence buffer should be initialized before executing this command.
add sid add side_chains | Add atoms which belong to side chains (all except CA, C, N and O).
add sma add small | Add small amino acids (GLY, ALA, SER, THR, CYS, VAL, PRO, ASP and ASN).
add sph add sphere | Add atoms inside the sphere. Use the command RAD (RADIUS) to set the sphere radius.
add tin add tiny | Add tiny amino acids (GLY,ALA and SER).
add tm | Add the transmembrane part (useful for membrane proteins).
add tra add trans | Add trans residues.
add tri add triplet | If there are three (or more) positively charged residues in a fragment of up to five protein residues, add these residues to the current set of selected atoms. Detailed explanation may found in the article: D. Juretic, L. Zoranic and D. Zucic, Basic charge clusters and predictions of membrane protein topology, Journal of Chemical Information and Computer Sciences 42, No. 3, 620-632 (2002).
add 2c3 | If there are two (or more) charged residues in a fragment of three residues, add these residues to the current selection.
add 2cz3 | If there are two (or more) charged or zwitterionic residues in a fragment of three residues, add these residues to the current selection.
add 2nz3 add 3c4 add 3cz4 add 3nz4 add 3c5 add 3cz5 add 3nz5 add 3p5 add 4c5 add 4cz5 add 4nz5 add 3c6 add 3cz6 add 3nz6 add 4c6 add 4cz6 add 4nz6 add 5c6 add 5cz6 add 5nz6 add 4c7 add 4cz7 add 4nz7 add 5c7 add 5cz7 add 5nz7 add 5p7 add 6p7 add 4c9 add 4cz9 add 4nz9 add 5c9 add 5cz9 add 5nz9 | Analogous to add 2c3 and add 2cz3, where c stands for charged , cz for charged or zwitterionic , nz for negative or zwitterionic and p for polar . The same selection criteria may be defined using patterns, but these short keywords are more practical.
add 3p5 | If there are three or more polar residues in a fragment of five residues, add these residues. The following residues are treated as polar: ARG, LYS, HIS, ASP, GLU, ASN, GLN, SER, THR, TYR and TRP.
add 5p7 | If there are five or more polar residues in a fragment of five residues, add these residues to the current selection. The following residues are treated as polar: ARG, LYS, HIS, ASP, GLU, ASN, GLN, SER, THR, TYR and TRP.
add 6p7 | If there are six or more polar residues in a fragment of five residues, add these residues to the current selection. The following residues are treated as polar: ARG, LYS, HIS, ASP, GLU, ASN, GLN, SER, THR, TYR and TRP.

EXPANDING SELECTION WITH
THE SPECIFIED CHEMICAL ELEMENT
To add certain chemical element to the selection, use the keyword ELEMENT (short form: ELE) and the standard chemical symbol. To expand your selection with iron atoms, for example, you should type the following command:
add ele fe
In addition to real chemical elements, garlic accepts two imaginary elements: "jellium" (J) and "quarkonium" (Q). Jellium is inert and it never binds to neighboring atoms, no matter how close they are. Quarkonium binds to other quarkonium atoms which have adjacent atomic serial numbers. For example, if some quarkonium atom has serial number i, it may form bonds with quarkonium atoms i-1 and i+1. The interatomic distance is not important! Both elements were introduced to enable drawing of special objects. Quarkonium may be used to draw polygonal lines in three dimensions. The original idea was to adapt garlic for visualization of some medical data. For example, quarkonium may be used to represent blood vessels and jellium to represent retraction balls characteristic for broken axons in human brain. By the way, quarkonium is a serious thing in high energy physics, but there it looks quite different. Note that symbols J and Q are not used in the periodic table of elements.
NOTES
(1) The command ADD resets the editing mode to default (no editing).
RELATED COMMANDS
EXPAND does exactly the same job as ADD. SELECT overwrites the previous selection. RESTRICT restrics the previous selection.